Percutaneous spinal implants and methods

ABSTRACT

An apparatus includes an elongate member having a portion configured to be deformed from a first configuration to a second configuration. In one variation, the apparatus includes an outer body, defining an interior region, and an inner body. A portion of the outer body is configured to be disposed between adjacent spinous processes. The inner body is disposed within the interior region of the outer body. A distal end portion of the inner body is coupled to a distal end portion of the outer body. A proximal end portion of the inner body configured to removably receive a tool to move the outer body between a collapsed configuration and an expanded configuration.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of International PatentApplication No. PCT/US2006/005580, entitled “Percutaneous SpinalImplants and Methods,” filed Feb. 17, 2006; which claims priority toU.S. patent application Ser. No. 11/059,526, entitled “Apparatus andMethod for Treatment of Spinal Conditions,” filed Feb. 17, 2005; U.S.Provisional Application Ser. No. 60/695,836 entitled “PercutaneousSpinal Implants and Methods,” filed Jul. 1, 2005; U.S. patentapplication Ser. No. 11/252,879, entitled “Percutaneous Spinal Implantsand Methods,” filed Oct. 19, 2005; and U.S. patent application Ser. No.11/252,880, entitled “Percutaneous Spinal Implants and Methods,” fieldOct. 19, 2005, each of which are incorporated herein by reference in itsentirety.

This application is related to U.S. patent application Ser. Nos.11/356,301, 11/356,302, 11/356,296, 11/356,295 and 11/356,294, eachentitled “Percutaneous Spinal Implants and Methods,” filed Febr. 17,2006, and incorporated herein by reference in their entirety.

This application is related to U.S. Patent Application Attorney DocketNos. KYPH-001/09US and KYPH-001/11US, each entitled “Percutaneous SpinalImplants and Methods,” filed on even date herewith, and incorporatedherein by reference in their entirety.

BACKGROUND

The invention relates generally to the treatment of spinal conditions,and more paritcularly, to the treatment of spinal compression usingpercutaneous spinal implants for implantatation between adjacent spinousprocesses.

A back condition that impacts many individuals is spinal stenosis.Spinal stenosis is a progressive narrowing of the spinal canal thatcauses compression of the spinal cord. Each vertebra in the spinalcolumn has an opening that extends through it. The openings are alignedvertically to form the spinal canal. The spinal cord runs through thespinal canal. As the spinal canal narrows, the spinal cord and nerveroots extending from the spinal cord and between adjacent vertebrae arecompressed and may become inflamed. Spinal stenosis can cause pain,weakness, numbness, burning sensations, tingling, and in particularlysevere cases, may cause loss of bladder or bowel function, or paralysis.The legs, calves and buttocks are most commonly affected by spinalstenosis, however, the shoulders and arms may also be affected.

Mild cases of spinal stenosis may be treated with rest or restrictedactivity, non-steroidal anti-inflammatory drugs (e.g., aspirin),corticosteroid injections (epidural steroids), and/or physical therapy.Some patients find that bending forward, sitting or Iying down may helprelieve the pain. This may be due to bending forward creates morevertebral space, which may temporarily relieve nerve compression.Because spinal stenosis is a progressive disease, the source of pressuremay have to be surgically corrected (decompressive laminectomy) as thepatient has increasing pain. The surgical procedure can remove bone andother tissues that have impinged upon the spinal canal or put pressureon the spinal cord. Two adjacent vertebrae may also be fused during thesurgical procedure to prevent an area of instability, improper alignmentor slippage, such as that caused by spondylolisthesis. Surgicaldecompression can relieve pressure on the spinal cord or spinal nerve bywidening the spinal canal to create more space. This procedure requiresthat the patient be given a general anesthesia as an incision is made inthe patient to access the spine to remove the areas that arecontributing to the pressure. This procedure, however, may result inblood loss and an increased chance of significant complications, andusually results in an extended hospital stay.

Minimally invasive procedures have been developed to provide access tothe space between adjacent spinous processes such that major surgery isnot required. Such known procedures, however, may not be suitable inconditions where the spinous processes are severely compressed.Moreover, such procedures typically involve large or multiple incisions.

Thus, a need exists for improvements in the treatment of spinalconditions such as spinal stenosis.

SUMMARY OF THE INVENTION

In one embodiment, apparatus includes an elongate member having aproximal portion configured to be deformed from a first configuration toa second configuration. The elongate member has a distal portionconfigured to be deformed from a first configuration to a secondconfiguration. A non-expanding central portion is positioned between theproximal portion and the distal portion. The non-expanding centralportion is configured to engage adjacent spinous processes.

In another embodiment, apparatus includes a guide shaft, an expansionmember coupled to the guide shaft, and an actuator. The expansion memberis configured to impart a force from within an interior of an implant todeform the implant. The actuator is coupled to the expansion member, theactuator is configured to move the expansion member from a firstposition to a second position.

In yet another embodiment, apparatus includes a first clamp having afirst end and a second end. The second end of the first clamp isconfigured to engage a first spinous process. A second clamp has a firstend and a second end. The second end of the second clamp is configuredto engage a second spinous process spaced apart from the first spinousprocess. A connector is coupled to the first end of the first clamp andthe first end of the second clamp.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a posterior view of a medicaldevice according to an embodiment of the invention in a firstconfiguration adjacent two adjacent spinous processes.

FIG. 2 is a schematic illustration of a posterior view of a medicaldevice according to an bodiment of the invention in a secondconfiguration adjacent two adjacent spinous processes.

FIG. 3 is a schematic illustration of a deforming element according toan embodiment of the invention in a first configuration.

FIG. 4 is a schematic illustration of a side view of the expandingelement illustrated in FIG. 3.

FIG. 5 is a side view of a medical device according to an embodiment ofthe invention in a first configuration.

FIG. 6 is a side view of the medical device illustrated in FIG. 5 in asecond configuration.

FIG. 7 is a perspective view of a medical device according to anembodiment of the invention in a first configuration.

FIG. 8 is a posterior view of a medical device according to anembodiment of the invention, a portion of which is in a secondconfiguration.

FIG. 9 is a posterior view of the medical device illustrated in FIG. 7fully deployed in the second configuration.

FIG. 10 is a front plan view of the medical device illustrated in FIG. 7in the second configuration.

FIG. 11 is a cross-sectional, side view of a medical device according toanother embodiment of the invention in a first configuration.

FIG. 12 is a cross sectional, side view of the medical deviceillustrated in FIG. 11 in a partially expanded configuration.

FIG. 13 is a posterior view of the medical device illustrated in FIG. 11inserted between adjacent spinous processes in a second configuration.

FIG. 14 is a lateral view of the medical device illustrated in FIG. 11inserted between adjacent spinous processes in a second configuration.

FIG. 15 is a perspective view of an implant expansion device accordingto an embodiment of the invention.

FIG. 1 5A is a cross-sectional view of a portion of the deviceillustrated in FIG. 15, taken along line A-A in FIG. 15.

FIG. 15B is a cross-sectional view of a portion of the deviceillustrated in FIG. 15 in a first configuration, taken along line B-B inFIG. 15.

FIG. 15C is a cross-sectional view of a portion of the deviceillustrated in FIG. 15 in a second configuration, taken along line C-Cin FIG. 15.

FIG. 16 is an alternative perspective view of the implant expansiondevice illustrated in FIG. 15.

FIG. 17 is a perspective view of a portion of the implant expansiondevice illustrated in FIG. 15.

FIG. 18 is a perspective view of an implant expansion device accordingto an embodiment of the invention in a first position.

FIG. 19 is a perspective view of the implant expansion deviceillustrated in FIG. 18 in a second position.

FIG. 20 is a partial cross-sectional illustration of the implantexpansion device as illustrated in FIG. 18 inserted in a spinal implant.

FIG. 21 is a partial cross-sectional illustration of the implantexpansion device as illustrated in FIG. 19 inserted in a spinal implant.

FIG. 22 is a side view of a partially expanded spinal implant.

FIG. 23 is a side view of an expanded spinal implant.

FIG. 24 is a cross-sectional, side view of an implant expansion deviceaccording to an alternative embodiment of the invention in a firstconfiguration.

FIG. 25 is a cross-sectional, side view of the implant expansion deviceillustrated in FIG. 24 in a second configuration.

FIG. 26 is a cross-sectional, plan view of an implant expansion deviceaccording to a further embodiment of the invention in a firstconfiguration.

FIG. 27 is a partial side view of an implant for use with the implantexpansion device illustrated in FIG. 26.

FIG. 28 is a cross-sectional, plan view of the implant expansion deviceillustrated in FIG. 26 in a second configuration.

FIG. 29 is a cross-sectional, plan view of an implant expansion deviceaccording to another embodiment of the invention in a firstconfiguration.

FIG. 30 is a cross-sectional, side view of the implant expansion deviceillustrated in FIG. 29.

FIGS. 31 and 32 illustrate a posterior view of a spinal implantexpandable by an expansion device implant expander according to anotherembodiment of the invention in a first configuration and a secondconfiguration, respectively.

FIG. 33 illustrates a cross-sectional, side view of a spinal implantaccording to an embodiment of the invention.

FIG. 34 is a cross-sectional, side view and FIG. 35 is a side view of animplant expansion device according to an embodiment of the invention foruse with the spinal implant illustrated in FIG. 33.

FIGS. 36 and 37 illustrate the use of the implant expansion deviceillustrated in FIGS. 34 and 35 with the spinal implant illustrated inFIG. 33.

FIG. 38 is a schematic illustration of an apparatus according to anembodiment of the invention.

FIG. 39 is a front plan view of an apparatus according to an embodimentof the invention and a portion of a spine. FIG. 40 is a cross-sectionalview of a component of the apparatus and the portion of the spineillustrated in FIG. 39, taken along line 40-40 in FIG. 39.

FIG. 41 is a side plan view of the apparatus illustrated in FIG. 39.

FIG. 42 is a side plan view of a component of the apparatus illustratedin FIG. 39.

FIG. 43 is a front plan view of the component of the apparatusillustrated in FIG. 42.

FIG. 44 is a partial cross-sectional view of a detachable trocar tip foruse with an apparatus according to an embodiment of the invention in afirst configuration.

FIG. 45 is a partial cross-sectional view of the detachable trocar tipfor use with the apparatus according to an embodiment of the inventionin a second configuration.

FIG. 46 is a partial exploded view of a detachable trocar tip for usewith the apparatus according to an embodiment of the invention.

FIG. 47 is a side plan view of a medical device according to anotherembodiment of the invention.

FIG. 48 is a perspective view of a medical device according to anotherembodiment of the invention.

FIG. 49 a is a perspective view of an apparatus according to anembodiment of the invention.

FIG. 49 b is an exploded view of a portion of the apparatus illustratedin FIG. 49 a.

FIG. 49c is an exploded view of a portion of the apparatus illustratedin FIG. 49 a.

FIG. 50 is a perspective view of a spacer configured to be insertedbetween spinous processes according to an embodiment of the invention.

FIG. 51 is a side view of a spacer according to an embodiment of theinvention in a first configuration inserted between adjacent spinousprocesses.

FIG. 52 is a side view of the spacer illustrated in FIG. 49 in a secondconfiguration inserted between adjacent spinous processes.

FIGS. 53-55 are illustrations of spacers according to alternativeembodiments of the invention.

FIG. 56 is a side view of a spacer according to an alternativeembodiment of the invention in in a first configuration.

FIG. 57 is a side view of the spacer illustrated in FIG. 56 in a secondconfiguration inserted between adjacent spinous processes.

FIG. 58 is a side view of a spacer according to a further alternativeembodiment of the invention inserted between adjacent spinous processes.

FIG. 59 is a side view of a spacer according to another alternativeembodiment of the invention inserted between adjacent spinous processes.

FIGS. 60A-60D are schematic illustrations of a posterior view of amedical device according to an embodiment of the invention in a firstconfiguration (FIG. 60A), a second (FIGS. 60B and 60D) configuration anda third configuration (FIG. 60C).

FIGS. 61A-61C are schematic illustrations of a posterior view of amedical device according to an embodiment of the invention in a firstconfiguration, a second consiguration and a third configuration,respectively.

FIGS. 62A-62F are posterior views of a medical device according to anembodiment of the invention inserted between adjacent spinous processesin a first lateral positions and a second lateral position.

FIG. 63 is a lateral view of the medical device illustrated in FIGS.62A-62F inserted between adjacent spinous processes in a secondconfiguration.

FIG. 64 is a lateral view of a medical device according to an embodimentof the invention inserted between adjacent spinous processes in a secondconfiguration.

FIGS. 65A and 65B are front views of a medical device according to anembodiment of the invention in a first configuration and a secondconfiguration, respectively.

FIG. 66A is a schematic illustration of a posterior view of a medicaldevice according to an embodiment of the invention in a firstconfiguration disposed between two adjacent spinous processes.

FIG. 66B is a schematic illustration of a posterior view of a medicaldevice acording to an embodiment of the invention in a secondconfiguration disposed between two adjacent spinous processes.

FIGS. 67A and 67B are perspective views of a medical device according toan embodiment of the invention in a first configuration and a secondconfiguration, respectively.

FIG. 68 is a posterior view of the medical device illustrated in FIGS.67A and 67B disposed between adjacent spinous processes in a secondconfiguration.

FIG. 69 is a lateral view taken from a proximal perspective A-A of themedical device illustrated in FIG. 68 disposed between adjacent spinousprocesses in a second configuration.

FIG. 70 is a cross-sectional front view of the medical deviceillustrated in FIGS. 67A and 67B in a second configuration.

FIG. 71 is a cross-sectional plan view taken along section A-A of themedical device illustrated in FIGS. 67A and 67B in a secondconfiguration.

FIG. 72 is a cross-sectional front view of a medical device according toan embodiment of the invention in a second configuration.

FIGS. 73A and 73B are cross-sectional plan views taken along section A-Aof the medical device illustrated in FIG. 72 in a second configurationand a first configuration, respectively.

FIG. 74 is a cross-sectional front view of a medical device according toan embodiment of the invention in a second configuration.

FIGS. 75A through 75C are cross-sectional plan views taken along sectionA-A of the medical device illustrated in FIG. 74 in a secondconfiguration, a first configuration, and a thrid configurationrespectively.

FIGS. 76A and 76B are cross-sectional front views of a medical deviceaccording to an embodiment of the invention in a second configurationand a first configuration, respectively.

FIG. 77 is a cross-sectional front view of a medical device according toan embodiment of the invention in a second configuration.

FIG. 78 is a cross-sectional plan view taken along section A-A of themedical device illustrated in FIG. 77 in a second configuration.

FIGS. 79A and 79B are perspective views of a medical device according toan embodiment of the invention in a second configuration and a firstconfiguration, respectively.

FIGS. 80A and 80B are lateral views of a medical device according to anembodiment of the invention in a first configuration and a secondconfiguration, respectively.

FIGS. 81A and 81B are perspective views of the medical deviceillustrated in FIGS. 80A and 80B in a first configuration and a secondconfiguration, respectively.

FIG. 82 is a cross-sectional plan view of the medical device illustratedin FIGS. 80A smf 80B in a second configuration.

FIG. 83 is a schematic illustration of a medical device according to anembodiment of the invention in a collapsed configuration adjacent twospinous processes.

FIG. 84 is a schematic illustration of the medical device of FIG. 83 inan expanded configuration adjacent two spinous processes.

FIG. 85 is a side perspective view of an implant according to anembodiment of the invention in an expanded configuration.

FIG. 86 is a side perspective view of the implant of FIG. 85 shown in acollapsed congiguration.

FIG. 87 is a side perspective view of the medical device of FIG. 85shown in a collapsed configuration.

FIG. 88 is a side view of a deployment tool according to an embodimentof the invention.

FIG. 89 is a side view of a portion of the deployment tool of FIG. 88shown in a first configuration.

FIG. 90 is a side view of the portion of the deployment tool of FIG. 89shown in a second configuration.

FIG. 91 is a side view of a portion of the deployment tool of FIG. 89and the implant of FIG. 85 with the implant shown in an expandedconfiguration.

FIG. 92 is a cross-sectional view of the portion of the deployment tooland implant shown in FIG. 91.

FIG. 93 is a cross-sectional view of the deployment tool and implant ofFIG. 91 with the implant shown in a collapsed configuration positionedbetween adjacent spinous processes.

FIG. 94 is a side view of a portion of a medical device according to anembodiment of the invention illustrating an engaging portion in anextended configuration and positioned adjacent a spinous process.

FIG. 95 is a side view of the portion of the medical device of FIG. 94illustrating the engaging portion in a partially collapsedconfiguration.

FIG. 96 is a side view of the portion of the medical device of FIG. 94illustrating the engaging portion in the extended configuration afterbeing inserted past the spinous process.

FIG. 97 is a side perspective view of the implant of FIG. 85 shownrotated about a longitudinal axis of the implant.

FIG. 98 is a side perspective view of an implant according to anotherembodiment of the invention.

FIG. 99 is a side view of a deployment tool according to anotherembodiment of the invention.

FIG. 100 is a side view of a deployment tool according to anotherembodiment of the invention.

FIG. 101 is a side view of a deployment tool according to anotherembodiment of the invention.

FIG. 102 is a side view of a deployment tool according to anotherembodiment of the invention.

FIG. 103 is a flow chart of a method according to an embodiment of theinvention.

FIG. 104 is a schematic illustration of a posterior view of a medicaldevice according to an embodiment of the invention in a firstconfiguration adjacent two adjacent spinous processes.

FIG. 105 is a schematic illustration of a posterior view of a medicaldevice according to an embodiment of the invention in a secondconfiguration adjacent two adjacent spinous rocesses.

FIG. 106 is a schematic illustration of a deforming element according toan embodiment of the invention in a first configuration.

FIG. 107 is a schematic illustration of a side view of the expandingelement illustrated in FIG. 106.

FIG. 108 is a side cross-sectional view of a medical device according toan embodiment of the invention in a first configuration.

FIG. 109 is a side cross-sectional view of the medical deviceillustrated in FIG. 108 in a second configuration.

FIG. 110 is a cross-sectional side view of a medical device and anactuator according to an embodiment of the invention with a portion ofthe medical device deployed in a second configuration.

FIG. 111 is a side cross-sectional view of a medical device and anactuator according to an embodiment of the invention with the medicaldevice fully deployed in the second configuration.

FIG. 112 is a side cross-sectional view of a medical device according toanother embodiment of the invention in a first configuration.

FIG. 113 is a side cross-sectional view of the medical deviceillustrated in FIG. 112 in a second configuration.

FIG. 114 is a side cross-sectional view of a medical device and anactuator according to an embodiment of the invention with a portion ofthe medical device moved back to its first configuration.

FIG. 115 is a side cross-sectional view of a medical device and anactuator according to an embodiment of the invention with the medicaldevice moved back to its first configuration.

FIG. 116 is a side cross-sectional view of a medical device and anactuator according to an embodiment of the invention with a portion ofthe medical device moved back to its first configuration.

FIG. 117 is a side cross-sectional view of a medical device and anactuator according to an embodiment of the invention with the medicaldevice moved back to its first configuration.

FIG. 118 is a side perspective view of an implant according to anembodiment of the invention shown in a collapsed configuration.

FIG. 119 is a cross-sectional view of the implant of FIG. 118 takenalong line 119-119.

FIG. 120 is a side perspective view of the implant of FIG. 118 shown inan expanded configuration.

FIG. 121 is a rear perspective view of the implant of FIG. 118 shown ina collapsed configuration.

FIG. 122 is cross-sectional view of the implant of FIG. 118 shown in acollapsed configuration taken along line 122-122.

FIG. 123 is a rear perspective view of an implant according to anembodiment of the invention shown in a collapsed configuration.

FIG. 124 is a cross-sectional view of the implant of FIG. 123 shown in acollapsed configuration.

FIG. 125 is a perspective view of the implant of FIG. 123 in a collapsedconfiguration disposed on an expansion tool according to an embodimentof the invention.

FIG. 126 is a perspective view of the implant and the expansion tool ofFIG. 125 taken along region 126.

FIG. 127 is a side cross-sectional view of the implant and the expansiontool of FIG. 125.

FIG. 128 is a side cross-sectional view of the implant and the expansiontool as shown in FIG. 127 taken along region 128.

FIG. 129 is a perspective view of the implant of FIG. 123 in an expandedconfiguration disposed on an expansion tool according to an embodimentof the invention.

FIG. 130 is a perspective view of the implant and the expansion tool ofFIG. 129 taken along region 130.

FIG. 131 is a side cross-sectional view of the implant and the expansiontool of FIG. 129.

FIG. 132 is a side cross-sectional view of the implant and the expansiontool as shown in FIG. 131 taken along region 132.

DETAILED DESCRIPTION

As used in this specification and the appended claims, the singularforms “a,” “an” and “the” include plural referents unless the contextclearly dictates otherwise. Thus, for example, the term “a member” isintended to mean a single member or a combination of members, “amaterial” is intended to mean one or more materials, or a combinationthereof. Furthermore, the words “proximal” and “distal38 refer todirection closer to and away from, respectively, an operator (e.g.,surgeon, physician, nurse, technician, etc.) who would insert themedical device into the patient, with the tip-end (i.e., distal end) ofthe device inserted inside a patient's body first. Thus, for example,the implant end first inserted inside the patient's body would be thedistal end of the implant, while the implant end to last enter thepatient's body would be the proximal end of the implant.

In one embodiment, apparatus includes an elongate member having aproximal portion configured to be deformed from a first configuration toa second configuration under, for example, an axial load or a radialload. The elongate member has a distal portion configured to be deformedfrom a first configuration to a second configuration under, for example,an axial load or a radial load. A non-expanding central portion ispositioned between the proximal portion and the distal portion. Thenon-expanding central portion is configured to engage adjacent spinousprocesses.

In some embodiments of the invention, the elongate member can havemultiple portions that each move from a first configuration to a secondconfiguration, either simultaneously or serially. Additionally, thedevice, or portions thereof, can be in many positions during themovement from the first configuration to the second configuration. Forease of reference, the entire device is referred to as being in either afirst configuration or a second configuration.

FIG. 1 is a schematic illustration of a medical device according to anembodiment of the invention adjacent two adjacent spinous processes. Themedical device 10 includes a proximal portion 12, a distal portion 14and a central portion 16. The medical device 10 has a firstconfiguration in which it can be inserted between adjacent spinousprocesses S. The central portion 16 is configured to contact the spinousprocesses S to prevent over-extension/compression of the spinousprocesses S. In some embodiments, the central portion 16 does notsubstantially distract the adjacent spinous processes S. In otherembodiments, the central portion 16 does not distract the adjacentspinous processes S.

In the first configuration, the proximal portion 12, the distal portion14 and the central portion 16 are coaxial (i.e., share a commonlongitudinal axis). In some embodiments, the proximal portion 12, thedistal portion 14 and the central portion 16 define a tube having aconstant inner diameter. In other embodiments, the proximal portion 12,the distal portion 14 and the central portion 16 define a tube having aconstant outer diameter and/or inner diameter.

The medical device 10 can be moved from the first configuration to asecond configuration as illustrated in FIG. 2. In the secondconfiguration, the proximal portion 12 and the distal portion 14 arepositioned to limit lateral movement of the device 10 with respect tothe spinous processes S. The proximal portion 12 and the distal portion14 are configured to engage the spinous process (i.e., either directlyor through surrounding tissue) in the second configuration. For purposesof clarity, the tissue surrounding the spinous processes S is notillustrated.

In some embodiments, the proximal portion 12, the distal portion 14 andthe central portion 16 are monolithically formed. In other embodiments,one or more of the proximal portion 12, the distal portion 14 and thecentral portion 16 are separate components that can be coupled togetherto form the medical device 10. For example, the proximal portion 12 anddistal portion 14 can be monolithically formed and the central portioncan be a separate component that is coupled thereto.

In use, the spinous processes S can be distracted prior to inserting themedical device 10. Distraction of spinous processes is discussed below.When the spinous processes are distracted, a trocar can be used todefine an access passage for the medical device 10. In some embodiments,the trocar can be used to define the passage as well as distract thespinous processes S. Once an access passage is defined, the medicaldevice 10 is inserted percutaneously and advanced between the spinousprocesses, distal end 14 first, until the central portion 16 is locatedbetween the spinous processes S. Once the medical device 10 is in placebetween the spinous processes, the proximal portion 12 and the distalportion 14 are moved to the second configuration, either serially orsimultaneously.

In some embodiments, the medical device 10 is inserted percutaneously(i.e., through an opening in the skin) and in a minimally invasivemanner. For example, as discussed in detail herein, the size of portionsof the implant is expanded after the implant is inserted between thespinous processes. Once expanded, the size of the expanded portions ofthe implant is greater than the size of the opening. For example, thesize of the opening/incision in the skin may be between 3 millimeters inlength and 25 millimeters in length. In some embodiments, the size ofthe implant in the expanded configuration is between 3 and 25millimeters.

FIG. 3 is a schematic illustration of a deformable element 18 that isrepresentative of the characteristics of, for example, the distalportion 14 of the medical device 10 in a first configuration. Thedeformable member 18 includes cutouts A, B, C along its length to defineweak points that allow the deformable member 18 to deform in apredetermined manner. Depending upon the depth d of the cutouts A, B, Cand the width w of the throats T1, T2, T3, the manner in which thedeformable member 18 deforms under an applied load can be controlled andvaried. Additionally, depending upon the length L between the cutouts A,B, C (i.e., the length of the material between the cutouts) the mannerin which the deformable member 18 deforms can be controlled and varied.

FIG. 4 is a schematic illustration of the expansion properties of thedeformable member 18 illustrated in FIG. 3. When a load is applied, forexample, in the direction indicated by arrow X, the deformable member 18deforms in a predetermined manner based on the characteristics of thedeformable member 18 as described above. As illustrated in FIG. 4, thedeformable member 18 deforms most at cutouts B and C due to theconfiguration of the cutout C and the short distance between cutouts Band C. In some embodiments, the length of the deformable member 18between cutouts B and C is sized to fit adjacent a spinous process.

The deformable member 18 is stiffer at cutout A due to the shallow depthof cutout A. As indicated in FIG. 4, a smooth transition is defined bythe deformable member 18 between cutouts A and B. Such a smoothtransition causes less stress on the tissue surrounding a spinousprocess than a more drastic transition such as between cutouts B and C.The dimensions and configuration of the deformable member 18 can alsodetermine the timing of the deformation at the various cutouts. Theweaker (i.e., deeper and wider) cutouts deform before the stronger(i.e., shallower and narrower) cutouts.

FIGS. 5 and 6 illustrate a spinal implant 100 in a first configurationand second configuration, respectively. As shown in FIG. 5, the spinalimplant 100 is collapsed in a first configuration and can be insertedbetween adjacent spinous processes. The spinal implant 100 has a firstexpandable portion 110, a second expandable portion 120 and a centralportion 150. The first expandable portion 110 has a first end 112 and asecond end 1140. The second expandable portion 120 has a first end 122and a second end 124. The central portion 150 is coupled between secondend 1140 and first end 122. In some embodiment, the spinal implant 100is monolithically formed.

The first expandable portion 110, the second expandable portion 120 andthe central portion 150 have a common longitudinal axis A along thelength of spinal implant 100. The central portion 150 can have the sameinner diameter as first expandable portion 110 and the second expandableportion 120. In some embodiments, the outer diameter of the centralportion 150 is smaller than the outer diameter of the first expandableportion 110 and the second expandable portion 120.

In use, spinal implant 100 is inserted percutaneously between adjacentspinous processes. The first expandable portion 110 is inserted firstand is moved past the spinous processes until the central portion 150 ispositioned between the spinous processes. The outer diameter of thecentral portion 150 can be slightly smaller than the space between thespinous processes to account for surrounding ligaments and tissue. Insome embodiments, the central portion directly contacts the spinousprocesses between which it is positioned. In some embodiments, thecentral portion of spinal implant 100 is a fixed size and is notcompressible or expandable.

The first expandable portion 110 includes expanding members 115, 117 and119. Between the expanding members 115, 117, 119, openings 111 aredefined. As discussed above, the size and shape of the openings 111influence the manner in which the expanding members 115, 117, 119 deformwhen an axial load is applied. The second expandable portion 120includes expanding members 125, 127 and 129. Between the expandingmembers 125, 127, 129, openings 121 are defined. As discussed above, thesize and shape of the openings 121 influence the manner in which theexpanding members 125, 127, 129 deform when an axial load is applied.

When an axial load is applied to the spinal implant 100, the spinalimplant 100 expands to a second configuration as illustrated in FIG. 6.In the second configuration, first end 112 and second end 1140 of thefirst expandable portion 110 move towards each other and expandingmembers 115, 117, 119 project substantially laterally away from thelongitudinal axis A. Likewise, first end 122 and second end 124 of thesecond expandable portion 120 move towards one another and expandingmembers 125, 127, 129 project laterally away from the longitudinal axisA. The expanding members 115, 117, 119, 125, 127, 129 in the secondconfiguration form projections that extend to positions adjacent to thespinous processes between which the spinal implant 100 is inserted. Inthe second configuration, the expanding members 115, 117, 119, 125, 127,129 inhibit lateral movement of the spinal implant 100, while thecentral portion 150 prevents the adjacent spinous processes from movingtogether any closer than the distance defined by the diameter of thecentral portion 150.

A spinal implant 200 according to an embodiment of the invention isillustrated in FIGS. 7-9 in various configurations. Spinal implant 200is illustrated in a completely collapsed configuration in FIG. 7 and canbe inserted between adjacent spinous processes. The spinal implant 200has a first expandable portion 210, a second expandable portion 220 anda central portion 250. The first expandable portion 210 has a first end212 and a second end 214. The second expandable portion 220 has a firstend 222 and a second end 224. The central portion 250 is coupled betweensecond end 214 and first end 222.

The first expandable portion 210, the second expandable portion 220 andthe central portion 250 have a common longitudinal axis A along thelength of spinal implant 200. The central portion 250 can have the sameinner diameter as first expandable portion 210 and the second expandableportion 220. The outer diameter of the central portion 250 is greaterthan the outer diameter of the first expandable portion 210 and thesecond expandable portion 220. The central portion 250 can bemonolithically formed with the first expandable portion 210 and thesecond expandable portion 220 or can be a separately formed sleevecoupled thereto or thereupon.

In use, spinal implant 200 is inserted percutaneously between adjacentspinous processes S. The first expandable portion 210 is inserted firstand is moved past the spinous processes S until the central portion 250is positioned between the spinous processes S. The outer diameter of thecentral portion 250 can be slightly smaller than the space between thespinous processes S to account for surrounding ligaments and tissue. Insome embodiments, the central portion 250 directly contacts the spinousprocesses S between which it is positioned. In some embodiments, thecentral portion 250 of spinal implant 200 is a fixed size and is notcompressible or expandable. In other embodiments, the central portion250 can compress to conform to the shape of the spinous processes.

The first expandable portion 210 includes expanding members 215, 217 and219. Between the expanding members 215, 217, 219, openings 211 aredefined. As discussed above, the size and shape of the openings 211influence the manner in which the expanding members 215, 217, 219 deformwhen an axial load is applied. Each expanding member 215, 217, 219 ofthe first expandable portion 210 includes a tab 213 extending into theopening 211 and an opposing mating slot 218. In some embodiments, thefirst end 212 of the first expandable portion 210 is rounded tofacilitate insertion of the spinal implant 200.

The second expandable portion 220 includes expanding members 225, 227and 229. Between the expanding members 225, 227, 229, openings 221 aredefined. As discussed above, the size and shape of the openings 221influence the manner in which the expanding members 225, 227, 229 deformwhen an axial load is applied. Each expanding member 225, 227, 229 ofthe second expandable portion 220 includes a tab 223 extending into theopening 221 and an opposing mating slot 228.

When an axial load is applied to the spinal implant 200, the spinalimplant moves to a partially expanded configuration as illustrated inFIG. 8. In the partially expanded configuration, first end 222 andsecond end 224 of the second expandable portion 220 move towards oneanother and expanding members 225, 227, 229 project laterally away fromthe longitudinal axis A. To prevent the second expandable portion 220from over-expanding, the tab 223 engages slot 228 and acts as a positivestop. As the axial load continues to be imparted to the spinal implant200 after the tab 223 engages slot 228, the load is transferred to thefirst expandable portion 210. Accordingly, the first end 212 and thesecond end 214 then move towards one another until tab 213 engages slot218 in the fully expanded configuration illustrated in FIG. 9. In thesecond configuration, expanding members 215, 217, 219 project laterallyaway from the longitudinal axis A. In some alternative embodiments, thefirst expandable portion and the second expandable portion expandsimultaneously under an axial load.

The order of expansion of the spinal implant 200 can be controlled byvarying the size of openings 211 and 221. For example, in theembodiments shown in FIGS. 7-9, the opening 221 is slightly larger thanthe opening 211. Accordingly, the notches 226 are slightly larger thanthe notches 216. As discussed above with respect to FIGS. 3 and 4, forthis reason, the second expandable portion 220 will expand before thefirst expandable portion 210 under an axial load.

In the second configuration, the expanding members 215, 217, 219, 225,227, 229 form projections that extend adjacent the spinous processes S.Once in the second configuration, the expanding members 215, 217, 219,225, 227, 229 inhibit lateral movement of the spinal implant 200, whilethe central portion 250 prevents the adjacent spinous processes frommoving together any closer than the distance defined by the diameter ofthe central portion 250.

The portion P of each of the expanding members 215, 217, 219, 225, 227,229 proximal to the spinous process S expands such that portion P issubstantially parallel to the spinous process S. The portion D of eachof the expanding members 215, 217, 219, 225, 227, 229 distal from thespinous process S is angled such that less tension is imparted to thesurrounding tissue.

In the second configuration, the expanding members 225, 227, 229 areseparate by approximately 120 degrees from an axial view as illustratedin FIG. 10. While three expanding members are illustrated, two or moreexpanding members may be used and arranged in an overlapping orinterleaved fashion when multiple implants 200 are inserted betweenmultiple adjacent spinous processes. Additionally, regardless of thenumber of expanding members provided, the adjacent expanding membersneed not be separated by equal angles or distances.

The spinal implant 200 is deformed by a compressive force impartedsubstantially along the longitudinal axis A of the spinal implant 200.The compressive force is imparted, for example, by attaching a rod (notillustrated) to the first end 212 of the first expandable portion 210and drawing the rod along the longitudinal axis while imparting anopposing force against the second end 224 of the second expandableportion 220. The opposing forces result in a compressive force causingthe spinal implant 200 to expand as discussed above.

The rod used to impart compressive force to the spinal implant 200 canbe removably coupled to the spinal implant 200. For example, the spinalimplant 200 can include threads 208 at the first end 212 of the firstexpandable portion 210. The force opposing that imparted by the rod canbe applied by using a push bar (not illustrated) that is removablycoupled to the second end 224 of the second expandable portion 220. Thepush rod can be aligned with the spinal implant 200 by an alignmentnotch 206 at the second end 224. The spinal implant 200 can also bedeformed in a variety of other ways, examples of which are discussed indetail below.

FIGS. 11-14 illustrate a spinal implant 300 according to an embodimentof the invention. Spinal implant 300 includes an elongated tube 310configured to be positioned between adjacent spinous processes S andhaving a first end 312 and a second end 314. The elongated tube 310 haslongitudinal slots 311 defined along its length at predeterminedlocations. The slots 311 are configured to allow portions of theelongated tube 310 to expand outwardly to form projections 317. Aninflatable member 350 is disposed about the elongated tube betweenadjacent sets of slots 311.

The inflatable member 350 is configured to be positioned betweenadjacent spinous processes S as illustrated in FIGS. 11-14. Onceinserted between the adjacent spinous processes, the inflatable member350 is inflated with a liquid and/or a gas, which can be, for example, abiocompatible material. The inflatable member 350 is inflated tomaintain the spinal implant 300 in position between the spinousprocesses S. In some embodiments, the inflatable member 350 isconfigured to at least partially distract the spinous processes S wheninflated. The inflatable member 350 can be inflated to varied dimensionsto account for different spacing between spinous processes S.

The inflatable member 350 can be inflated via an inflation tube 370inserted through the spinal implant 300 once spinal implant 300 is inposition between the spinous processes S. Either before or after theinflatable member 350 is inflated, the projections 317 are expanded. Toexpand the projections 317, an axial force is applied to the spinalimplant 300 using draw bar 320, which is coupled to the first end 312 ofthe spinal implant 300.

As the draw bar 320 is pulled, the axial load causes the projections 317to buckle outwardly, thereby preventing the spinal implant from lateralmovement with respect to the dpinoud processes S. FIG. 12 is anillustration of the spinal implant 300 during deformation, theprojections 317 being only partially formed. Although illustrated asdeforming simulaneously, the slots 311 alternatively can be dimensionedsuch that the deformation occurs at different times as described above.Once the spinal implant is in the expanded configuration (see FIG. 13),the draw bar 320 is removed from the elongated tube 310.

The orientation of the spinal implant 300 need not be such that twoprojections are substantially parallel to the axis of the portion of thespine to which they are adjacent as illustrated in FIG. 14. For example,the spinal implant 300 can be oriented such that each of the projections317 is at a 45 degree angle with respect to the spinal axis.

The spinal implants 100, 200, 300 can be deformed from their firstconfiguration to their second configuration using a variety of expansiondevices. For example, portions of the spinal implants 100, 200, 300, aswell as other types of implants I, can be deformed using expansiondevices described below. While various types of implants I areillustrated, the various expansion devices described can be used withany of the implants described herein.

FIGS. 15-17 illustrate an embodiment of an expansion device 1500 (alsoreferred to herein as an insertion tool or a deployment tool). Theexpansion device 1500 includes a guide handle 1510, a knob assembly1515, a shaft 1520, a rod 1570 and an implant support portion 1530. Theexpansion device 1500 is used to insert an implant (not illustrated) inbetween adjacent spinous processes and expand the implant such that itis maintained in position between the spinous processes as describedabove. Both the guide handle 1510 and the knob assembly 1515 can begrasped to manipulate the expansion device 1500 to insert the implant.As described in more detail herein, the knob assembly 1515 is configuredsuch that as the knob assembly 1515 is actuated, the rod 1570 translatesand/or rotates within the shaft 1520; when the rod 1570 translates, theimplant (not illustrated) is moved between its collapsed configurationand its expanded configuration; when the rod 1570 rotates, the implantis disengaged from the rod 1570. While no particular implant isillustrated in FIGS. 15-17, for purposes of clarity, an implant such as,for example, implant 200 (see FIG. 7) can be used with the expansiondevice 1500.

As best illustrated in FIG. 15B, the implant support portion 1530includes a receiving member 1538 and a spacer 1532. The receiving member1538 includes a side wall 1540 that is coupled to and supported by thedistal end of the shaft 1520. The side wall 1540 defines an alignmentprotrusion 1536 and a receiving area 1542 configured to receive aportion of the spacer 1532. The implant slides over spacer 1532 untilits proximal end is received within a recess 1534 defined by the sidewall 1540 and the outer surface of the spacer 1532. The alignmentprotrusion 1536 is configured to mate with a corresponding notch on theimplant (see, e.g., alignment notch 206 in FIG. 7) to align the implantwith respect to the expansion device. Once the implant is aligned withinthe implant support portion 1530, the distal end of the implant isthreadedly coupled to the distal end of rod 1570.

As illustrated, the spacer 1532 ensures that the implant is alignedlongitudinally during the insertion and expansion process. The spacer1532 can also be configured to maintain the shape of the implant duringinsertion and to prevent the expandable portions of the implant fromextending inwardly during deployment of the implant. For example, insome embodiments, the spacer 1532 can be constructed from a solid,substantially rigid material, such as stainless steel, having an outerdiameter and length corresponding to the inner diameter and length ofthe implant. In other embodiments, the expansion device can beconfigured to be used with implants that include an inner coreconfigured to provide structural support to the implant (see, forexample, FIGS. 118-124). In such embodiments, as described in moredetail herein, the spacer of the insertion tool can be configured tocooperate with the inner core of the implant to provide the alignmentand structural support of the implant during insertion and expansion.

The knob assembly 1515 includes an upper housing 1517 that threadedlyreceives the shaft 1520, an actuator knob 1550 and a release knob 1560as best illustrated in FIG. 15A. Upper housing 1517 includes internalthreads 1519 that mate with external threads 1521 on shaft 1520. Theproximal end of rod 1570 is coupled to the knob assembly 1515 by anadapter 1554, which is supported by two thrust bearings 1552. Actuatorknob 1550 is coupled to the upper housing 1517 and is engaged with theadapter 1554 such that when actuator knob 1550 is turned in thedirection indicated by arrows E (see FIG. 17), the rod 1570 translatesaxially relative to the shaft 1520 towards the proximal end of thedevice 1500, thereby acting as a draw bar and opposing the movement ofthe implant in the distal direction. In other words, when the implant isinserted between adjacent spinous processes and the actuator knob 1515is turned, the distal end of the implant support portion 1530 imparts anaxial force against the proximal end of the implant, while the rod 1570causes an opposing force in the proximal direction. In this manner, theforces imparted by the implant support portion and the rod 1570 causeportions of the implant to expand in a transverse configuration suchthat the implant is maintained in position between the spinous processesas described above. The expansion device 1500 can also be used to movethe implant from its expanded configuration to its collapsedconfiguration by turning the actuator knob 1550 in the oppositedirection.

Once the implant is in position and fully expanded, the release knob1560 is turned in the direction indicated by arrow R (see FIG. 17)thereby causing the rod 1570 to rotate within the shaft 1520. In thismanner, the implant can be disengaged from the rod 1570. During thisoperation, the implant is prevented from rotating by the alignmentprotrusion 1536, which is configured to mate with a corresponding notchon the implant. Once the implant is decoupled from the rod 1570, theexpansion tool 1500 can then be removed from the patient.

Although the knob assembly 1515 is shown and described as including anactuator knob 1550 and a release knob 1560 that are coaxially arrangedwith a portion of the release knob 1560 being disposed within theactuator knob 1550, in some embodiments, the release knob is disposedapart from the actuator knob. In other embodiments, the release knob andthe actuator knob are not coaxially located. In yet other embodiments,the knob assembly 1515 does not include knobs having a circular shape,but rather includes levers, handles or any other device suitable foractuating the rod relative to the shaft as described above.

FIG. 18 illustrates a portion of expansion device 400 in a collapsedconfiguration. Expansion device 400 can be used to selectively formprotrusions on the implant I (not illustrated in FIG. 18) at desiredlocations. The expansion device 400 includes a guide shaft 410, whichcan guide the expansion device 400 into the implant I and a cam actuator450 mounted thereto and positionable into an eccentric position. Theexpansion device 400 has a longitudinal axis A and the cam actuator 450has a cam axis C that is laterally offset from the longitudinal axis Aby a distance d. FIG. 19 illustrates the expansion device 400 in theexpanded configuration with the cam actuator 450 having been rotatedabout the cam axis C.

The expansion device 400 can be inserted into an implant I through animplant holder H as illustrated in FIG. 20. The implant holder H iscoupled to the implant and is configured to hold the implant in positionwhile the expansion device 400 is being manipulated to deform theimplant I. Once the implant I is satisfactorily deformed, the implantholder H can be detached from the implant I and removed from thepatient, leaving the implant I behind.

Referring to FIGS. 20 and 21, the expansion device 400 includes a handle420 that is used to deploy the cam actuator 450. When the handle 420 isrotated, the cam actuator 450 is deployed and deforms the implant I.Once the cam actuator 450 is fully deployed (e.g., 180 degrees from itsoriginal position) and locked in place, the entire expansion device 400is rotated to deform the implant I around the circumference of implantI. The cam actuator 450 circumscribes a locus of points that is outsidethe original diameter of the implant I, forming the projection P (seeFIG. 22). The expansion device 400 can be rotated either by grasping theguide shaft 410 or by using the handle 420 after it has been locked inplace.

The expansion device 400 can be used to form multiple projections P.Once a first projection P is formed, the cam actuator 450 can be rotatedback to its first configuration and the expansion device 400 advancedthrough the implant I to a second position. When the expansion device400 is appropriately positioned, the cam actuator 450 can again bedeployed and the expansion device 400 rotated to form a secondprojection P (see FIG. 23). In some embodiments, the implant I ispositioned between adjacent spinous processes and the projections P areformed on the sides of the spinous processes to prevent lateral (i.e.,axial) displacement of the implant I.

An alternative expansion device 500 is illustrated in FIGS. 24 and 25.FIG. 24 illustrates the expansion device 500 in a first configurationand FIG. 25 illustrates the expansion device 500 in a secondconfiguration. The expansion device 500 includes a guide shaft 510 thatis inserted into an implant 1. An axial cam shaft actuator 520 isslidably disposed within the guide shaft 520. The axial cam shaftactuator 520 has a sloped recess 530 to receive a movable object 550.When the cam shaft actuator 520 is moved, the movable object 550 isdisplaced along the sloped recess 530 until it protrudes through anopening 540 in the guide shaft 510.

The movable object 550 is configured to displace a portion of theimplant I, thereby forming a projection P. Multiple movable objects 550can be used around the circumference of the guide shaft 510 to form aradially extending protrusions P around the circumference of the implant1. Additionally, the protrusions can be formed at multiple locationsalong the length of the implant I by advancing the expansion device 500along the length of the implant to a second position as discussed above.Alternatively, the expansion device can have multiple recesses thatdisplace other sets of movable objects.

In alternative embodiments, the expansion device can also serve as animplant. For example, the expansion device 500 can be inserted betweenadjacent spinous processes S, the movable objects moved out throughopenings 540, and the expansion device 500 left behind in the body. Insuch an embodiment, the movable objects prevent the expansion device 500from lateral movement with respect to the spinous processes S.

In another alternative embodiment, rather than having openings 540 inthe expansion device 500, the movable objects 550 can be positionedagainst a weaker (e.g., thinner) portion of the wall of the expansiondevice and move that portion of the expansion device 500 to a protrudedconfiguration.

Another alternative expansion device 600 is illustrated in FIGS. 26-28.FIG. 26 illustrates the expansion device 600 in a first configurationand FIG. 28 illustrates the expansion device in a second configuration.The expansion device 600 includes a guide shaft 610 that is insertedinto an implant 1. The guide shaft 610 has openings 640 defined therein.An axial cam shaft actuator 620 is rotatably coupled within the guideshaft 610. Displaceable objects 650 are positioned within the guideshaft 610 and are configured to protrude through the openings 640 in theguide shaft 610. When the cam shaft actuator 620 is rotatedapproximately 90 degrees, the movable objects 650 move through theopenings 640 and deform the implant I, forming the projection P.Alternatively, the expansion device can have multiple cams that displaceother sets of movable objects.

Multiple movable objects 650 can be used around the circumference of theguide shaft 610 to form radially extending protrusions P around theimplant 1. Additionally, the protrusions can be formed at multiplelocations along the length of the implant I by advancing the expansiondevice 600 along the length of the implant I to a second position asdiscussed above.

An implant expansion device 700 is illustrated in FIGS. 29 and 30. Theimplant expansion device 700 is configured to be inserted into animplant 1. The implant 700 includes a guide shaft 710 coupled to ahousing 770. A cam actuator 720 is rotatably mounted within the housing770 and includes arms 790 that extend in opposite directions from oneanother. The cam actuator 720 is rotated using rod 722.

As the cam actuator 720 rotates, the arms 790 engage movable objects750. The movable objects 750 are configured to project out of thehousing 770 when the cam actuator is rotated in a clockwise manner. Oncethe movable objects 750 are fully extended, they engage the implant Iand the expansion device 700 can be rotated a complete revolution toform a protrusion in the implant I.

After one protrusion is formed, the rod 722 can be rotatedcounterclockwise to disengage the movable objects 750 from the implant1. Once disengaged, the expansion device 700 can be advanced to anotherlocation within the implant I as discussed above.

In some other embodiments, the implant I can be balloon actuated. FIG.31 illustrates an implant I positioned between adjacent spinousprocesses S. A balloon actuator 800 in inserted into the implant I andexpanded as illustrated in FIG. 32 to move the implant I to its expandedconfiguration. Once expanded, the balloon actuator 800 can be deflatedand removed, leaving the implant I in an expanded configuration.

In some embodiments, the balloon actuator 800 can have multiple lobes,one that expands on each side of the spinous process S. In otherembodiments, multiple balloon actuators 800 can be used to expand theimplant 1.

FIG. 33 is a cross-sectional view of an expandable implant 900 that canbe expanded using an expansion device 950, illustrated in FIGS. 34-37.The implant 900 has an elongated body portion 910 having a first end 901and a second end 902. The first end 901 has an externally threadedportion 911 and the second end 902 has an internally threaded portion912. The implant 900 has a first outer diameter D1 at the externallythreaded portion 911 and a second outer diameter D2, which wider thanthe first outer diameter D1.

The expansion device 950 includes a draw bar 960 and a compression bar970. In some embodiments, the compression bar 970 defines a channel 975having internal threads 971 to mate with the externally threaded portion911 of the implant 900 (see FIG. 34). The draw bar 960 has externalthreads 961 to mate with the internally threaded portion 912 of implant900.

In use, the compression bar 970 is coupled to the first end 901 of theimplant 900 and abuts the implant 900 at the transition between thefirst outer diameter D1 and the second outer diameter D2, which servesas a stop for the compression bar 970. In some embodiments, the outerdiameter of the entire implant 900 is substantially constant and theinner diameter of the compression bar 970 narrows to serve as the stopfor the compression bar 970. With the compression bar 970 in place, thedraw bar 960 is inserted through the channel 975 and is coupled to thesecond end 902 of the implant 900 via the internally threaded portion912 of implant 900 (see FIG. 35). Once the compression bar 970 and thedraw bar 960 are coupled to the implant 900, the draw bar 960 can bepulled while imparting an opposing force on the compression bar 970 toexpand the implant 900 (see FIG. 36). When the implant 900 is fullyexpanded, the compression bar 970 and the draw bar 960 are removed andthe implant is left behind in the body.

With the expansion devices described herein, the location of protrusionscan be selected in vivo, rather than having predetermined expansionlocations. Such a configuration reduces the need to have multiple sizesof spacers available. Additionally, the timing of the deployment of theprotrusions can be varied.

The various implants 100, 200, 300 described herein can be made from,for example, stainless steel, plastic, polyetheretherketone (PEEK),carbon fiber, ultra-high molecular weight (UHMW) polyethylene, etc. Thematerial can have a tensile strength similar to or higher than that ofbone.

In other embodiments of the invention, an apparatus includes a firstclamp having a first end and a second end. The second end of the firstclamp is configured to engage a first spinous process. A second clamphas a first end and a second end. The second end of the second clamp isconfigured to engage a second spinous process spaced apart from thefirst spinous process. A connector is coupled to the first end of thefirst clamp and the first end of the second clamp.

FIG. 38 is a schematic illustration of a medical device according to anembodiment of the invention attached to two adjacent spinous processes.The apparatus 1010 includes a first clamp 1012 configured to be coupledto a first spinous process S and a second clamp 1014 configured to becoupled to a second spinous process S. The first clamp 1012 and thesecond clamp 1014 are configured to be moved apart from one another inthe direction indicated by arrows X. As the first clamp 1012 and thesecond clamp 1014 are moved apart, an opening between adjacent spinousprocesses S expands. An insert 1050 can be inserted between the spinousprocesses S in the direction indicated by arrow Y to maintain theopening between the spinous processes S. The clamps 1012, 1014 engagethe spinous processes S with sufficient force such that when the clamps1012, 1014 are spread apart, they cause lateral displacement of thespinous processes S.

FIG. 39 is a side view of a medical device according to an embodiment ofthe invention coupled to a portion of a spine. The tissue surroundingthe spine is not illustrated for the sake of clarity. The medical device1000 includes a first clamp 1100 and a second clamp 1200. The firstclamp 1100 has a proximal end 1120 and a distal end 1140. The distal end1140 of the first clamp 1100 is configured to engage a first spinousprocess S. The second clamp 1200 has a first end 1220 and a second end1240. The second end 1240 of the second clamp 1200 is configured toengage a second spinous process S that is spaced apart from the firstspinous process S.

A connector 1300 is coupled to the proximal end 1120 of the first clamp1100 and the first end 1220 of the second clamp 1200. The position ofthe connector 1300 relative to the first clamp 1100 and the second clamp1200 can be adjusted such that the distance between the first clamp 1100and the second clamp 1200 can be adjusted. In other words, the connector1300 is reconfigurable between a first configuration and a secondconfiguration. The first clamp 1100 is a first distance from the secondclamp 1200 when the connector 1300 is in its first configuration and isa second distance from the second clamp 1200 when the connector 1300 isin its second configuration.

Referring to FIG. 40, in which the first clamp 1100 is illustrated, thefirst clamp 1100 includes a first jaw 1150 and a second jaw 1130opposite the first jaw 11 50. The first jaw 1150 and the second jaw 1130are configured to be movable between a first configuration and a secondconfiguration. The first jaw 1150 and the second jaw 1130 are closertogether in the second configuration than in the first configuration. Inthe second configuration, the first jaw 1150 and the second jaw 1130engage the spinous process S with sufficient force to substantiallymaintain the orientation of the first clamp 1100 and the second clamp1200 with respect to the spinous process S when the connector 1300 ismoved to its second configuration, thereby spreading the spinousprocesses S. The second clamp 1200 has a similar configuration, but isnot illustrated for ease of reference. The material of the jaws 1150,1130 are such that they can sufficiently engage the spinous processes Sas described, but to not damage the spinous processes. Adequatematerials include, for example, stainless steel, polyetheretherketone(PEEK), carbon fiber, ultra-high molecular weight (UHMW) polyethylene,etc. The material can have a tensile strength similar to or higher thanthat of bone. In some embodiments, the clamp 1200 can be manufacturedfrom stainless steel and a coating and/or an over-mold or over-layer ofPEEK or carbon fiber can be applied to the jaws 1150, 1130.

In some embodiments, the medical device 100 is used to spread adjacentspinous processes of severely compressed vertebrae. Additionally, themedical device 100 stabilizes the spinous processes during procedureswithout penetrating the vertebrae.

In some embodiments, the first clamp 1100 includes a first arm 1170 anda second arm 1180 and a tension member 1160. The first arm 1170 andsecond arm 1180 can be resiliently coupled such that as tension member1160 is advanced towards the distal end 1140 of the clamp 1100, thefirst arm 1170 and the second arm 1180 are moved towards one another,but as the tension member 1160 is moved away from the distal end 1140 ofthe clamp 1100, the first arm 1170 and the second arm 1180 return totheir default position (i.e., spaced apart).

The tension member 1160 is configured to move the first jaw 1150 and thesecond jaw 1130 between their first configuration and their secondconfiguration as the first arm 1170 and the second arm 1180 move towardsone another. As the tension member 1160 is moved towards the first jaw11 50 and the second jaw 1130, the first jaw 1150 and the second jaw1130 engage the spinous process S. In some applications, a distal end1140 of the clamp 1100 is positioned adjacent the lamina L of thevertebra to which it is coupled. In some embodiments, the clamp 1100 isattached close to the lamina L to minimize the lever arm on the spinousprocess. The distal end 1140 of clamp 1100 need not penetrate the laminaL.

In an alternative embodiment, the tension member includes threads thatengage threads on the first clamp. In such an embodiment, the tensionmember is moved along the length of the first clamp by turning thetension member. Returning to FIG. 40, the tension member 1160 mayoptionally include a tapered portion 1190 that matingly engages atapered portion 1110 of first clamp 1100. Such a configuration canensure appropriate distribution of the forces to the spinous process S.The second clamp 1200 is similarly configured and includes a tensionmember 126 and opposing jaws.

A swing arm 1700 is pivotably coupled to the connector 1300 between thefirst clamp 1100 and the second clamp 1200. The swing arm 1700 has anarcuate portion 173 and travels along a range of motion. The arcuateportion 173 of the swing arm 1700 has a first end 1750 and a second end1770.

As best seen in FIGS. 41 and 42, the second end 1770 of the arcuateportion 173 of swing arm 1700 is configured to receive a working tool1840, such as, for example, a pointed trocar tip. The swing arm 1700defines an opening 1740 in which at least a portion of the working tool1840 is received. In some embodiments, the opening 1740 extends alongthe entire length of the arcuate portion 173 between the first end 1750and the second end 1770. In some embodiments, an optional handle 190 canbe coupled to the first clamp 1100 and/or the second clamp 1200 tofacilitate insertion of the clamps 1100, 1200 and increase stability ofthe apparatus 1000 during use.

The working tool 1840 is coupled to a guide wire 1860. The guide wire1860 has a first end 1810 and a second end 1830. The second end 1830 ofthe guide wire 1860 is coupled to the working tool 1840. A retainer 1820(discussed in detail below) is coupled to the first end 1810 of theguide wire 1860 and is configured to maintain the position of theworking tool 1840 with respect to the swing arm 1700. The retainer 1820is matingly received in a recess 1720 in the swing arm 1700. The guidewire 1860 is received in the opening 1740 defined in the swing arm 1700.The guide wire is received in the opening 1740 through a channel 1760defined in the swing arm 1700 as best seen in FIG. 43. In somealternative embodiments, the guide wire does not extend through theopening 1740 of the swing arm 1700. In yet other alternativeembodiments, the guide wire is not present.

FIGS. 44 and 45 illustrate the retainer 1820 in a first configurationand a second configuration, respectively. The retainer 1820 includes ahousing 1880 that defines an opening 1870 through which guide wire 1860is movably disposed. The guide wire 1860 is coupled to a retentionmember 1830. The retention member 1830 is biased towards a first end1890 of housing 1880 by a spring 1850. The spring 1850 is between asecond end 1810 of the housing 1880 and the retention member 1830.

In use, when the retainer 1850 is in the first configuration (FIG. 44),the working tool is maintained in the swing arm 1700. When the retainer1820 is moved to its second configuration (FIG. 45), the working tool1840 can be removed from the swing arm 1700. When moved to the secondconfiguration, the retainer 1820 is displaced a distance d, therebyincreasing the effective length of the guide wire 1860, allowingmovement of the working tool 1840 with respect to the end of the swingarm 1700. In some embodiments, the distance d is approximately the sameas the length of the portion of the working tool 1840 received in theswing arm 1700.

As shown in FIG. 46, a working tool 1840′ is inserted into an opening1740′ defined by a swing arm 1700′. The swing arm 1700′ includes aprojection 1920 within opening 1740′ that mates with a recess 1970 onworking tool 1840′.

Returning to FIGS. 39-42, in use, a first clamp 1100 is inserted througha body B and coupled to a spinous process S. The tension member 1160 ismoved towards the distal end 1140 of the first clamp to engage the firstjaw 150 and the second jaw 1130 with the spinous process S. The secondclamp 1200 is then inserted and similarly coupled to the adjacentspinous process S. The connector 1300 is actuated to increase thedistance between the first clamp 1100 and the second clamp 1200, therebyseparating the adjacent spinous processes S. Once the spinous processesS are separated, the swing arm 1700 is moved through its range of motionM.

The swing arm 1700 is moved from a location outside a body B through arange of motion M (see, e.g., FIG. 41). The swing arm 1700 enters thebody B and moves through range of motion M until it is at target T (see,e.g., FIG. 39) between adjacent spinous processes S.

The movement of the swing arm 1700 into the body defines a path withinthe tissue (not illustrated). The tissue is penetrated by a pointedprojection (i.e., working tool 1840). The path M defined by the swingarm 1700 includes the target T between the adjacent spinous processes S.Once the path is defined, the swing arm 1700 can be removed and a spacer500 (see FIG. 49), discussed in detail below, can be inserted betweenthe adjacent spinous processes S. In some embodiments of the invention,the spacer 5000 can be removably attached to the swing arm 1700,inserted into the body and then removed from the swing arm 1700.

A medical device 2000 according to an embodiment of the invention isillustrated in FIG. 47. Medical device 2000 includes a handle 2900coupled to an arm 2700. The arm 2700 has a first end 2750 and a secondend 2770 and defines an opening 2740 along its length. A working tool2840 can be received within opening 2740 adjacent the second end 2770.The arm 2700 also includes a recess 2720 to receive a retainer (notillustrated) similar to retainer 1850 discussed above. Medical device2000 is inserted between adjacent spinous process in a manner similar toswing arm 1700 discussed above. The depth and placement of the arm 2700,however is determined by the user of the medical device 2000. Such amedical device can be used with or without the benefit of the clamps1100, 1200 discussed above. In other words, the medical device 2000 canbe inserted between adjacent spinous processes S without firstseparating the spinous processes S.

A medical device according to another embodiment of the invention isillustrated in FIG. 48. Medical device 2010 is a distraction tool havinga handle 2011, a curved shaft 2020 and a distraction portion 2030. Thedistraction portion 2030 includes a pointed tip 2032 and an insertionposition indicator 2034. The medical device 2010 is inserted into apatient's back and moved in between adjacent spinous processes from theside of the spinous processes (i.e., a posterior-lateral approach). Theconfiguration of the curved shaft 2020 assists in the use of a lateralapproach to the spinous processes. The distraction portion 2030 definesa path through the patient's tissue and between the adjacent spinousprocesses.

The position indicator 2034 can be a physical ridge or detent such thatthe physician can identify through tactile sensation when the medicaldevice 2010 has been inserted an appropriate distance (e.g., when theposition indicator 2034 engages the spinous processes). The positionindicator 2034 can alternatively be a radioopaque strip that can beimaged using a fluoroscope. As a further alternative, multiplefluoroscopic markings (not illustrated) can be placed on the shaft 2020within the distraction portion 2030. The markings can be imaged todetermine the spacing between the spinous processes and/or the positionof the distraction portion 2030 relative to the spinous processes. Oncethe spinous processes are adequately distracted, the medical device 2010is removed. After the medical device 2010 is removed, an implant (notillustrated in FIG. 48) is positioned between spinous processes using aninsertion tool to limit the minimum distance between the spinousprocesses during their range of motion.

An alternative swing arm 1700″ for use with medical device 100 accordingto an embodiment of the invention is illustrated in FIGS. 49 a-49 c. Asbest seen in FIGS. 49a and 45 c, the second end 1770″ of swing arm 1700″is configured to receive a working tool 1840″, such as, for example, apointed trocar tip. The swing arm 1700″ defines an opening 1740″ inwhich at least a portion of the working tool 1840″ is received. In someembodiments, the opening 1740″ extends along the entire length of theswing arm 1700″ between the first end 1750″ and the second end 1770″ todefine a passageway or lumen. The opening 1740″ is slightly larger thanthe diameter of the working tool 1840″ such that the working tool 1840″is positioned within the opening 1740″ during use.

The working tool 1840″ is coupled to a wire 1860″. The wire 1860″ has afirst end 1810″ and a second end 1830″. The second end 1830″ of the wire1860″ is coupled to the working tool 1840″. A retainer 1820″ (discussedin detail below) is coupled to the first end 1810″ of the wire 1860″ andis configured to maintain the position of the working tool 1840″ withrespect to the swing arm 1700″. In some embodiments, the wire 1860″ issubstantially rigid such that the working tool 1840″ is not retractedinto the opening 1740″ when force is imparted against the working tool1840″.

The retainer 1820″ is received in a recess 1720″ in the swing arm 1700″.The retainer 1820″ is maintained in the recess 1720″ using threadedfasteners 173″. In some alternative embodiments, the wire 1860″ does notextend through the opening 1740″ of the swing arm 1700″. In yet otheralternative embodiments, the wire 1860″ is not present.

FIGS. 50-59 illustrate various spacers 5000 that can be inserted betweenadjacent spinous processes S. Once the spacer 5000 is inserted betweenthe spinous processes S, depending upon the type of spacer 5000, thespacer 5000 can be deformed to be held in place. For example, in someembodiments, a balloon actuator 5500 can be inserted into the spacer andexpanded, thereby expanding the ends of the spacer 5000 to retain thespacer 5000 between the spinous processes S (see, e.g., FIGS. 50, 52 and56). Once the spacer 5000 is expanded, the balloon actuator 5500 can bedeflated and removed (see, e.g., FIG. 57).

In some embodiments of the invention, the spacer 5000 includes an endportion 5750 that includes a recess 5970 that is configured to mate withthe projection 1920 on swing arm 1700′ (see FIG. 46).

In another embodiment, a method includes percutaneously inserting into abody an expandable member having a first configuration, a secondconfiguration and a third configuration. The expandable member includesa support portion and a retention portion. The support portion has alongitudinal axis and is configured to be disposed between adjacentspinous processes. The retention portion is configured to limit movementof the support portion along the longitudinal axis. When the expandablemember is in the first configuration, it is disposed in a first locationbetween the adjacent spinous processes. The expandable member is thenexpanded from the first configuration to the second configuration. Theexpandable member is then contracted from the second configuration tothe third configuration and disposed in a second location, the secondlocation being different from the first location.

In some embodiments, an apparatus includes an expandable member having asupport portion, a retention portion, a first configuration, and asecond configuration. The support portion has a longitudinal axis and isconfigured to be disposed between adjacent spinous processes. Theretention portion is disposed adjacent to the support portion and isconfigured to limit movement of the support portion along thelongitudinal axis. When in the first configuration, the expandablemember has a first volume. When in the second configuration, theexpandable member has a second volume, the second volume being greaterthan the first volume. The expandable member is configured to move fromthe first configuration to the second configuration and to move from thesecond configuration to the first configuration.

In some embodiments, the apparatus includes a sensor coupled to theexpandable member. The sensor can be, for example, a strain gauge sensoror a piezoelectric sensor that measures a force applied to theexpandable member and/or a pressure of a fluid within the expandablemember.

In some embodiments, an apparatus includes a substantially rigid supportmember, a first expandable member and a second expandable member. Thesupport member is configured to be disposed between adjacent spinousprocesses. The first expandable member is coupled to a proximal portionof the support member and has a first configuration in which it has afirst volume and a second configuration in which it has a second volume,which is greater than the first volume. Similarly, the second expandablemember is coupled to a distal portion of the support member and has afirst configuration in which it has a first volume and a secondconfiguration in which it has a second volume, which is greater than thefirst volume.

FIGS. 60A-60D are schematic illustrations of a posterior view of amedical device 4000 according to an embodiment of the inventionpositioned adjacent two adjacent spinous processes S in a firstconfiguration (FIG. 60A), a second configuration (FIGS. 60B and 60D) anda third configuration (FIG. 60C). The medical device 4000 includes anexpandable member 4002 having an inner area (not shown) and an outersurface 4010. The outer surface 4010 is configured to be disposedbetween the spinous processes S to prevent over-extension/compression ofthe spinous processes S. In some embodiments, the expandable member 4002distracts the adjacent spinous processes S. In other embodiments, theexpandable member 4002 does not distract the adjacent spinous processesS.

The expandable member 4002 has a first configuration, a secondconfiguration and a third configuration. When in each configuration, theexpandable member 4002 has an associated volume. As illustrated in FIG.60A, the first configuration represents a substantially contractedcondition in which the expandable member 4002 has a minimal volume. Whenthe expandable member 4002 is in the first configuration, the medicaldevice 4000 is inserted between the adjacent spinous processes S. Asillustrated in FIGS. 60B and 60D, the second configuration represents anexpanded condition in which the expandable member 4002 has a largevolume. When the expandable member 4002 is in the second configuration,the outer surface 4010 of the medical device 4000 contacts the adjacentspinous processes S during at least a portion of the range of motion ofthe spinous processes. As illustrated in FIG. 60C, the thirdconfiguration represents a partially expanded condition in which theexpandable member 4002 has a volume between that associated with thefirst configuration and that associated with the second configuration.When the expandable member 4002 is in the third configuration, themedical device 4000 can be repositioned between the adjacent spinousprocesses, as indicated by the arrow in FIG. 60C. The medical device canthen be subsequently re-expanded into the second configuration, asillustrated in FIG. 60D.

FIGS. 61A-61C are schematic illustrations of a posterior view of themedical device 4000 positioned adjacent two adjacent spinous processes Sin a first configuration, a second configuration and a thirdconfiguration, respectively. As described above, when the expandablemember 4002 is in the first configuration, the medical device 4000 isinserted between the adjacent spinous processes S. The expandable member4002 is then expanded to the second configuration, in which the outersurface 4010 of the medical device 4000 is disposed between the adjacentspinous processes S. The expandable member 4002 is then contracted tothe third configuration to facilitate removal of the medical device4000, as shown in FIG. 61C. In some embodiments, the third configurationcan be the same as the first configuration.

In use, the adjacent spinous processes S can be distracted prior toinserting the medical device 4000 into a body. Distraction of spinousprocesses described herein. When the spinous processes S are distracted,a trocar (not shown) can be used to define an access passageway (notshown) for the medical device 4000. In some embodiments, the trocar canbe used to define the passage as well as to distract the spinousprocesses S. Once an access passageway is defined, the medical device4000 is inserted percutaneously and advanced between the spinousprocesses S and placed in the desired position between the adjacentspinous processes S. Once the medical device 4000 is in the desiredposition, the expandable member is expanded to the second condition,causing the outer surface 4010 to engage the spinous processes S.

In some embodiments, the adjacent spinous processes can be distracted bya first expandable member (not shown) configured to distract bone. Upondistraction, the first expandable member is contracted and removed fromthe body. The medical device 4000 is then inserted percutaneously,advanced between the spinous processes S, placed in the desired positionand expanded, as described above.

In some embodiments, the medical device 4000 is inserted percutaneously(i.e., through an opening in the skin) and in a minimally-invasivemanner. For example, as discussed in detail herein, the overall sizes ofportions of the medical device 4000 are increased by transitioning theexpandable member 4002 from the first configuration to the secondconfiguration after the medical device 4000 is inserted between theadjacent spinous processes S. When in the expanded second configuration,the sizes of portions of the medical device 4000 are greater than thesize of the opening. For example, the size of the opening/incision inthe skin can be between 3 millimeters in length and 25 millimeters inlength across the opening. In some embodiments, the size of the medicaldevice 4000 in the expanded second configuration is between 3 and 25millimeters across the opening.

FIGS. 62A-62F are posterior views of a spinal implant 4100 according toan embodiment of the invention inserted between adjacent spinousprocesses S in a first lateral position (FIG. 62C) and a second lateralposition (FIG. 62E). The spinal implant 4100 includes an expandablemember 4102, a sensor 4112 and a valve 4132. The expandable member 4102has an inner area (not shown), an outer surface 4110, a support portion4118, a proximal retention portion 4114 and a distal retention portion4116. The expandable member 4102 is repeatably positionable in a firstconfiguration (FIG. 62B), a second configuration (FIGS. 62C, 62E and62F) and a third configuration (FIG. 62D). When in each configuration,the expandable member 4102 has an associated volume, as will bediscussed below.

In use, the spinal implant 4100 is positioned in the substantiallycontracted first configuration during insertion and/or removal (see FIG.62B). As discussed above, the spinal implant 4100 is insertedpercutaneously between adjacent spinous processes S. The distalretention portion 4116 of the expandable member 4102 is inserted firstand is moved past the spinous processes S until the support portion 4118is positioned between the spinous processes S. When in the firstconfiguration, the support portion 4118 can be can be sized to accountfor ligaments and tissue surrounding the spinous processes S. Forpurposes of clarity, such surrounding ligaments and tissue are notillustrated.

As illustrated in FIG. 62C, once in position, the expandable member 4102is expanded into the second configuration by conveying a fluid (notshown) from an area outside of the expandable member 4102 to the innerarea of the expandable member 4102. The fluid is conveyed by anexpansion tool 4130, such as a catheter, that is matingly coupled to thevalve 4132. The valve 4132 can be any valve suitable for sealablyconnecting the inner area of the expandable member 4102 to an areaoutside of the expandable member 4102. For example, in some embodiments,the valve 4132 can be, for example a poppet valve, a pinch valve or atwo-way check valve. In other embodiments, the valve includes a couplingportion (not shown) configured to allow the expansion tool 4130 to berepeatably coupled to and removed from the valve 4132. For example, insome embodiments, the valve 4132 can include a threaded portionconfigured to matingly couple the expansion tool 4130 and the valve4132.

The fluid is configured to retain fluidic properties while resident inthe inner area of the expandable member 4102. In this manner, the spinalimplant 4100 can be repeatably transitioned from the expanded secondconfiguration to the first configuration and/or the third configurationby removing the fluid from the inner area of the expandable member 4102.In some embodiments, the fluid can be a biocompatible liquid havingconstant or nearly constant properties. Such liquids can include, forexample, saline solution. In other embodiments, the fluid can be abiocompatible liquid configured to have material properties that changeover time while still retaining fluidic properties sufficient to allowremoval of the fluid. For example, the viscosity of a fluid can beincreased by adding a curing agent or the like. In this manner, thefluid can provide both the requisite structural support while retainingthe ability to be removed from the inner area of the expandable member4102 via the valve 4132. In yet other embodiments, the fluid can be abiocompatible gas.

The outer surface 4110 of the support portion 4118 can distract theadjacent spinous processes S as the expandable member 4102 expands tothe second configuration, as indicated by the arrows shown in FIG. 62C.In some embodiments, the support portion 4118 does not distract theadjacent spinous processes S. For example, as discussed above, theadjacent spinous processes S can be distracted by a trocar and/or anyother device suitable for distraction.

When in the second configuration, the outer surface 4110 of the supportportion 4118 is configured to engage the spinous processes S for atleast a portion of the range of motion of the spinous processes S toprevent over-extension/compression of the spinous processes S. In someembodiments, the engagement of the spinous processes S by the outersurface 4110 of the support portion 4118 is not continuous, but occursupon spinal extension.

When in the second configuration, the proximal retention portion 4114and the distal retention portion 4116 each have a size SI (shown in FIG.63) that is greater than the vertical distance D1 (shown in FIG. 63)between the spinous processes. In this manner, the proximal retentionportion 4114 and the distal retention portion 4116 are disposed adjacentthe sides of spinous processes S (i.e., either through direct contact orthrough surrounding tissue), thereby limiting movement of the spinalimplant 4100 laterally along a longitudinal axis of the support portion4118.

The expandable member 4102 can be made from any number of biocompatiblematerials, such as, for example, PET, Nylons, cross-linked Polyethylene,Polyurethanes, and PVC. In some embodiments, the chosen material can besubstantially inelastic, thereby forming a low-compliant expandablemember 4102. In other embodiments, the chosen material can have a higherelasticity, thereby forming a high-compliant expandable member 4102. Inyet other embodiments, the expandable member 4102 can be made from acombination of materials such that one portion of the expandable member4102, such as the support portion 4118, can be low-compliant while otherportions of the expandable member 4102, such as the proximal retentionportion 4114 and/or distal retention portion 4116 are more highlycompliant. In yet other embodiments, a portion of the expandable member4102 can include a rigid, inflexible material to provide structuralstiffness. For example, the support portion 4118 can be constructed of acomposite material that includes a rigid, inflexible material tofacilitate distraction of the adjacent spinous processes.

In some embodiments, the expandable member 4102 includes a radiopaquematerial, such as bismuth, to facilitate tracking the position of thespinal implant 4100 during insertion and/or repositioning. In otherembodiments, the fluid used to expand the expandable member 4102includes a radiopaque tracer to facilitate tracking the position of thespinal implant 4100.

In the illustrated embodiment, the spinal implant 4100 includes a sensor4112 coupled to the expandable member 4102. In some embodiments, thesensor 4112 is a strain gauge sensor that measures a force applied tothe support portion 4118 of the expandable member 4102. The sensor 4112can include multiple strain gauges to facilitate measuring multipleforce quantities, such as a compressive force and/or a tensile force. Inother embodiments, the sensor 4112 is a variable capacitance typepressure sensor configured to measure a force and/or a pressure of thefluid contained within the inner portion of the expandable member 4102.In yet other embodiments, the sensor 4112 is a piezoelectric sensor thatmeasures a pressure of the fluid contained within the inner portion ofthe expandable member 4102. In still other embodiments, the spinalimplant 4100 can include multiple sensors 4112 located at variouslocations to provide a spatial profile of the force and/or pressureapplied to the expandable member 4102. In this manner, a practitionercan detect changes in the patient's condition, such those that mayresult in a loosening of the spinal implant 4100.

In some embodiments, the sensor 4112 can be remotely controlled by anexternal induction device. For example, an external radio frequency (RF)transmitter (not shown) can be used to supply power to and communicatewith the sensor 4112. In other embodiments, an external acoustic signaltransmitter (not shown) can be used to supply power to and communicatewith the sensor 4112. In such an arrangement, for example, the sensorcan include a pressure sensor, of the types described above, formeasuring a pressure; an acoustic transducers, and an energy storagedevice. The acoustic transducer converts energy between electricalenergy and acoustic energy. The energy storage device stores theelectrical energy converted by the acoustic transducer and supplies theelectrical energy to support the operation of the pressure sensor. Inthis manner, acoustic energy from an external source can be received andconverted into electrical energy used to power the pressure sensor.Similarly, an electrical signal output from the pressure sensor can beconverted into acoustic energy and transmitted to an external source.

At times, the spinal implant 4100 may need to be repositioned. Suchrepositioning can be required, for example, to optimize the lateralposition of the support portion 4118 during the insertion process. Inother instances, the spinal implant 4100 can require repositioningsubsequent to the insertion process to accommodate changes in theconditions of the patient. In yet other instances, the spinal implant4100 can be removed from the patient. To allow for such repositioningand/or removal, the spinal implant is repeatably positionable in thefirst configuration, the second configuration and/or the thirdconfiguration. In FIG. 62D, for example, the expandable member 4102 iscontracted to the third configuration by removing all or a portion ofthe fluid contained in the inner area, as described above. In thismanner, the spinal implant 4100 can be repositioned in a lateraldirection, as indicated by the arrow. Once in the desired position, theexpandable member is reexpanded to the second condition as describedabove. Finally, as shown in FIG. 62F, the expansion tool 4130 is removedfrom the valve 4132.

FIG. 63 is a lateral view of the spinal implant 4100 illustrated inFIGS. 62A-62F inserted between adjacent spinous processes S in a secondconfiguration. Although FIG. 63 only shows the proximal retentionportion 4114 of the expandable member 4102, it should be understood thatthe distal retention portion 4116 has characteristics and functionalitysimilar to those described below for proximal retention portion 4114. Asillustrated, the proximal retention portion 4114 has a size S1 that isgreater than the vertical distance D1 between the spinous processes S.In this manner, the proximal retention portion 4114 and the distalretention portion 4116 limit the lateral movement of the spinal implant4100 when in the second configuration, as discussed above.

FIG. 64 is a lateral view of a spinal implant 4200 according to anembodiment of the invention inserted between adjacent spinous processesand in a second configuration. Similar to the spinal implant 4100discussed above, the spinal implant 4200 includes an expandable member4202 and a valve 4232. The expandable member 4202 has a support portion(not shown), a proximal retention portion 4214 and a distal retentionportion (not shown). The expandable member 4202 is repeatablypositionable in a first configuration, a second configuration and/or athird configuration. When in each configuration, the expandable member4202 has an associated volume, as discussed above.

In the illustrated embodiment, the proximal retention portion 4214 ofthe expandable member 4202 has a first radial extension 4236, a secondradial extension 4238 and a third radial extension 4240. As illustrated,the distance S1 between the ends of the radial extensions is greaterthan the vertical distance D1 between the spinous processes S. In thismanner, the proximal retention portion 4214 and the distal retentionportion limit the lateral movement of the spinal implant 4200 when inthe second configuration. In some embodiments, the proximal retentionportion and the distal retention portion can assume a variety ofdifferent shapes.

FIGS. 65A and 65B are front views of a spinal implant 4300 according toan embodiment of the invention in a first configuration and a secondconfiguration, respectively. The spinal implant 4300 includes a proximalexpandable member 4304, a distal expandable member 4306, a supportmember 4308, a sensor 4312 and a valve 4332. The support member 4308 hasan inner area (not shown) and an outer surface 4310. The outer surface4310 is configured to contact the spinous processes (not shown). In someembodiments, the support member 4308 distracts the adjacent spinousprocesses. In other embodiments, the support member 4308 does notdistract the adjacent spinous processes. In yet other embodiments, theengagement of the spinous processes by the support member 4308 is notcontinuous, but occurs upon spinal extension.

The support member 4308 has a proximal portion 4324, to which theproximal expandable member 4304 is coupled, and a distal portion 4326,to which the distal expandable member 4306 is coupled. The proximalexpandable member 4304 and the distal expandable member 4306 are eachrepeatably positionable in a first configuration (FIG. 65A) and a secondconfiguration (FIG. 65B). As described above, the first configurationrepresents a substantially contracted condition in which the proximalexpandable member 4304 and the distal expandable member 4306 each have aminimal volume. When the spinal implant 4300 is in the firstconfiguration, it can be inserted, repositioned and/or removed. In theillustrated embodiment, the proximal expandable member 4304 and thedistal expandable member 4306 are each contained within the inner areaof the support member 4308 when the spinal implant 4300 is in the firstconfiguration. In some embodiments, the proximal expandable member 4304and the distal expandable member 4306 are not contained within thesupport member 4308.

Conversely, the second configuration represents an expanded condition inwhich the proximal expandable member 4304 and the distal expandablemember 4306 each have a large volume. When the spinal implant 4300 is inthe second configuration, the proximal expandable member 4304 and thedistal expandable member 4306 each have a size that is greater than thevertical distance between the spinous processes, as described above. Inthis manner, the proximal expandable member 4304 and the distalexpandable member 4306 engage the spinous processes, thereby limitingthe lateral movement of the spinal implant 4300.

The proximal expandable member 4304 and the distal expandable member4306 are expanded into the second configuration by conveying a fluid(not shown) from an area outside of each expandable member 4304, 4306 toan inner area defined by each expandable member 4304, 4306. The fluid isconveyed through a valve 4332, as described above. In the illustratedembodiment, the inner area of the proximal expandable member 4304, theinner area of the distal expandable member 4306 and the inner area ofthe support member 4308 are in fluid communication with each other toform a single inner area. As such, the fluid can be conveyed to both theinner area of the proximal expandable member 4304 and the inner area ofthe distal expandable member 4306 by a single valve 4332. In someembodiments, the inner areas of the proximal expandable member 4304 andthe distal expandable member 4306 are not in fluid communication. Insuch an arrangement, each expandable member can be independentlytransformed between configurations.

The support member 4308 can be made from any number of biocompatiblematerials, such as, for example, stainless steel, plastic,polyetheretherketone (PEEK), carbon fiber, ultra-high molecular weight(UHMW) polyethylene, and the like. The material of the support member4308 can have a tensile strength similar to or higher than that of bone.In some embodiments, the support member 4308 is substantially rigid. Inother embodiments, the support member 4308 or portions thereof iselastically deformable, thereby allowing it to conform to the shape ofthe spinous processes. In yet other embodiments, the support member 4308includes a radiopaque material, such as bismuth, to facilitate trackingthe position of the spinal plant 4300 during insertion and/orrepositioning.

The proximal expandable member 4304 and the distal expandable member4306 can be made from any number of biocompatible materials, asdiscussed above. The proximal expandable member 4304 and the distalexpandable member 4306 can be coupled to the support member by ansuitable means, such as a biocompatible adhesive.

In the illustrated embodiment, the spinal implant 4300 includes a sensor4312 coupled to the support member 4308. As described above, the sensor4312 can be configured to measure multiple force quantities and/or apressure of the fluid contained within the proximal expandable member4304 and the distal expandable member 4306.

In another embodiment, the apparatus includes a support member, aproximal retemtion member, and a distal retention member. The supportmember is configured to be disposed between adjacent spinous processes.The proximal retention member has a first configuration in which theproximal retention member is substantially disposed within a proximalportion of the support member and a second configuration in which aportion of the proximal retention member is disposed outside of thesupport member. The distal retention member has a first configuration inwhich the distal retention member is substantially within a distalportion of the support member and a second configuration in which aportion of the distal retention member is disposed outside of thesupport member.

In some embodiments, each of the proximal retention member and thedistal retention member includes a first elongate member and a secondelongate member. The second elongate member is configured to be slidablydisposed within the first elongate member. The support member includes aside wall defining a multiple openings, each opening being configured toreceive a portion of at least one of the first elongate member or thesecond elongate member therethrough.

In some embodiments, each of the proximal retention member and thedistal retention member includes an elongate member having alongitudinal axis and a rotating member having a longitudinal axisnormal to the longitudinal axis of the elongate member. A portion of theelongate member is flexible in a direction normal to its longitudinalaxis. The rotating member is coupled to the elongate member andconfigured to rotate about its longitudinal axis, thereby moving theelongate member along its longitudinal axis.

In some embodiments, a method includes percutaneously inserting into abody a support member configured to be disposed between adjacent spinousprocesses. The support member defines an inner area and an openingsubstantially normal to the longitudinal axis that connects the innerarea and an area outside the support member. The support member includesa retention member having a first configuration in which the retentionmember is substantially disposed within the inner area, and a secondconfiguration in which a portion of the retention member is disposedthrough the opening to the area outside the support member. The supportmember is disposed to a location between the adjacent spinous processeswhen retention member is in the first configuration. The retentionmember is moved from the first configuration to the secondconfiguration.

Although specific portions of the apparatus, such as one or moreretention members, are configured to move between a first, a secondconfiguration and/or a third configuration, for ease of reference, theentire apparatus may be referred to as being in a first configuration, asecond configuration and/or a third configuration. However, one ofordinary skill in the art having he benefit of this disclosure wouldappreciate that the apparatus may be configured to include four or moreconfigurations. Additionally, in some embodiments, the apparatus can bein many positions during the movement between the first, second and/orthird configurations. For ease of reference, the apparatus is referredto as being in either a first configuration, a second configuration or athird configuration. Finally, in some embodiments, although an apparatusincludes one or more retention members, the figures and accompanyingdescription may show and describe only a single retention member. Insuch instances, it should be understood that the description of a singleretention member applies to some or all other retention members that maybe included in the embodiment.

FIGS. 66A and 66B are schematic illustrations of a posterior view of amedical device 3000 according to an embodiment of the invention disposedbetween two adjacent spinous processes S in a first configuration and asecond configuration, respectively. The medical device 3000 includes asupport member 3002, a proximal retention member 3010 and a distalretention member 3012. The support member 3002 has a proximal portion3004 and a distal portion 3006, and is configured to be disposed betweenthe spinous processes S to prevent over-extension/compression of thespinous processes S. In some embodiments, the support member 3002distracts the adjacent spinous processes S. In other embodiments, thesupport member 3002 does not distract the adjacent spinous processes S.

The proximal retention member 3010 has a first configuration in which itis substantially disposed within the proximal portion 3004 of thesupport member 3002, as illustrated in FIG. 66A. Similarly, the distalretention member 3012 has a first configuration in which it issubstantially disposed within the distal portion 3006 of the supportmember 3002. When the proximal retention member 3010 and the distalretention member 3012 are each in their respective first configuration,the medical device 3000 can be inserted between the adjacent spinousprocesses S.

The proximal retention member 3010 can be moved from the firstconfiguration to a second configuration in which a portion of it isdisposed outside of the support member 3002, as illustrated in FIG. 66B.Similarly, the distal retention member 3012 can be moved from the firstconfiguration to a second configuration. When each is in theirrespective second configuration, the proximal retention member 3010 andthe distal retention member 3012 limit lateral movement of the supportmember 3002 with respect to the spinous processes S by contacting thespinous processes S (i.e., either directly or through surroundingtissue). For purposes of clarity, the tissue surrounding the spinousprocesses S is not illustrated.

In use, the adjacent spinous processes S can be distracted prior toinserting the medical device 3000 into the patient. When the spinousprocesses S are distracted, a trocar (not shown in FIGS. 66A or 66B) canbe used to define an access passageway (not shown in FIGS. 66A and 66B)for the medical device 3000. In some embodiments, the trocar can be usedto define the passage as well as to distract the spinous processes S.

Once an access passageway is defined, the medical device 3000 isinserted percutaneously and advanced, distal portion 3006 first, betweenthe spinous processes S. The medical device 3000 can be inserted fromthe side of the spinous processes S (i.e., a posterior-lateralapproach). The use of a curved shaft assists in the use of a lateralapproach to the spinous processes S. Once the medical device 3000 is inplace between the spinous processes S, the proximal retention member3010 and the distal retention member 3012 are moved to their secondconfigurations, either serially or simultaneously. In this manner,lateral movement of the support member 3002 with respect to the spinousprocesses S is limited.

When it is desirable to change the position of the medical device 3000,the proximal retention member 3010 and the distal retention member 3012are moved back to their first configurations, thereby allowing thesupport member 3002 to be moved laterally. Once the support member 3002is repositioned, the medical device 3000 can be returned to the secondconfiguration. Similarly, when it is desirable to remove the medicaldevice 3000, proximal retention member 3010 and the distal retentionmember 3012 are moved to their first configurations, thereby allowingthe support member 3002 to be removed.

In some embodiments, the medical device 3000 is inserted percutaneously(i.e., through an opening in the skin) and in a minimally-invasivemanner. For example, as discussed in detail herein, the overall sizes ofportions of the medical device 3000 can be increased by moving theproximal retention member 3010 and the distal retention member 3012 totheir respective second configurations after the medical device 3000 isinserted between the adjacent spinous processes S. When in the expandedsecond configuration, the sizes of portions of the medical device 3000can be greater than the size of the opening. For example, the size ofthe opening/incision in the skin can be between 3 millimeters in lengthand 25 millimeters in length across the opening. In some embodiments,the size of the medical device 3000 in the expanded second configurationis between 3 and 25 millimeters across the opening.

FIGS. 67A, 67B, 68-71 illustrate a spinal implant 3100 according to anembodiment of the invention. FIGS. 67A and 67B are perspective views ofthe spinal implant 3100 in a first configuration and a secondconfiguration, respectively. The spinal implant 3100 includes a supportmember 3102, a proximal retention member 3110 and a distal retentionmember 3112. The support member 3102 is positioned between adjacentspinous processes S, as illustrated in FIGS. 68 and 69. As shown inFIGS. 67A and 67B, the proximal retention member 3110 and the distalretention member 3112 are each repeatably positionable in a firstconfiguration in which they are substantially disposed within thesupport member 3102 (FIG. 67A), and a second configuration in which aportion of each retention member 3110, 3112 is disposed outside of thesupport member 3102 (FIG. 67B). When the spinal implant 3100 is in thefirst configuration, it can be inserted between the adjacent spinousprocesses S, repositioned between the adjacent spinous processes and/orremoved from the patient. When the spinal implant 3100 is in the secondconfiguration, its lateral movement is limited, thereby allowing thedesired position of the support member 3102 to be maintained.

In some embodiments, the support member 3102 distracts the adjacentspinous processes S. In other embodiments, the support member 3102 doesnot distract the adjacent spinous processes S. In yet other embodiments,the engagement of the spinous processes S by the support member 3102 isnot continuous, but occurs upon spinal extension.

The support member 3102 can be made from any number of biocompatiblematerials, such as, for example, stainless steel, plastic,polyetheretherketone (PEEK), carbon fiber, ultra-high molecular weight(UHMW) polyethylene, and the like. The material of the support member3102 can have a tensile strength similar to or higher than that of bone.In some embodiments, the support member 3102 is substantially rigid. Inother embodiments, the support member 3102 or portions thereof iselastically deformable, thereby allowing it to conform to the shape ofthe spinous processes. In yet other embodiments, the support member 3102includes a radiopaque material, such as bismuth, to facilitate trackingthe position of the spinal implant 3100 during insertion and/orrepositioning.

In the illustrated embodiment, the spinal implant 3100 includes a sensor3124 coupled to the support member 3102. In some embodiments, the sensor3124 is a strain gauge sensor that measures a force applied to thesupport member 3102. In some embodiments, the sensor 3124 can includemultiple strain gauges to facilitate measuring multiple forcequantities, such as a compressive force and/or a bending moment. Inother embodiments, the sensor 3124 is a variable capacitance typepressure sensor configured to measure a force and/or a pressure appliedto the support member 3102. In yet other embodiments, the sensor 3124 isa piezoelectric sensor that measures a force and/or a pressure appliedto the support member 3102. In still other embodiments, the spinalimplant 3100 can include multiple sensors located at various locationsto provide a spatial profile of the force and/or pressure applied to thesupport member 3102. In this manner, a practitioner can detect changesin the patient's condition, such those that may result in a loosening ofthe spinal implant.

In some embodiments, the sensor 3124 can be remotely controlled by anexternal induction device. For example, an external radio frequency (RF)transmitter (not shown) can be used to supply power to and communicatewith the sensor 3124. In other embodiments, an external acoustic signaltransmitter (not shown) can be used to supply power to and communicatewith the sensor 3124. In such an arrangement, for example, the sensorcan include a pressure sensor, of the types described above, formeasuring a pressure; an acoustic transducers, and an energy storagedevice. The acoustic transducer converts energy between electricalenergy and acoustic energy. The energy storage device stores theelectrical energy converted by the acoustic transducer and supplies theelectrical energy to support the operation of the pressure sensor. Inthis manner, acoustic energy from an external source can be received andconverted into electrical energy used to power the pressure sensor.Similarly, an electrical signal output from the pressure sensor can beconverted into acoustic energy and transmitted to an external source.

The support member 3102 includes a sidewall 3108 that defines an innerarea 3120 and multiple openings 3114 that connect the inner area 3120 toan area outside of the support member 3102. When the spinal implant 3100is in the first configuration, the proximal retention member 3110 andthe distal retention member 3112 are substantially disposed within theinner area 3120 of the support member 3102, as shown in FIG. 67A. Whenthe spinal implant 3100 is in the second configuration, a portion ofeach of the proximal retention member 3110 and the distal retentionmember 3112 extends through the openings 3114 to an area outside of thesupport member 3102. In the second configuration, the proximal retentionmember 3110 and the distal retention member 3112 engage the adjacentspinous processes, thereby limiting lateral movement of the spinalimplant 3100.

The proximal retention member 3110 includes a first elongate member 3130and a second elongate member 3132. Similarly, the distal retentionmember 3112 includes a first elongate member 3131 and a second elongatemember 3133. As illustrated in FIG. 71, which shows is a cross-sectionalplan view of the proximal portion 3104 of the support member 3102, thefirst elongate member 3130 is slidably disposed within a pocket 3134defined by the second elongate member 3132. A biasing member 3136, suchas a spring or an elastic member, is disposed within the pocket 3134 andis coupled to the first elongate member 3130 and the second elongatemember 3132. In this manner, the retention members can be biased in thesecond configuration. In other embodiments, the biasing member 3136 canbe configured to bias the retention members in the first configuration.In yet other embodiments, the retention members do not include a biasingmember, but instead use other mechanisms to retain a desiredconfiguration. Such mechanisms can include, for example, mating tabs andslots configured to lockably engage when the retention members are in adesired configuration.

In use, the spinal implant 3100 is positioned in the first configurationduring insertion, removal or repositioning. As discussed above, thespinal implant 3100 is inserted percutaneously between adjacent spinousprocesses. The distal portion 3106 of the support member 3102 isinserted first and is moved past the spinous processes until the supportmember 3102 is positioned between the spinous processes. The supportmember 3102 can be sized to account for ligaments and tissue surroundingthe spinous processes S. In some embodiments, the support member 3102contacts the spinous processes between which it is positioned during aportion of the range of motion of the spinous processes S. In someembodiments, the support member 3102 of spinal implant 3100 is a fixedsize and is not compressible or expandable. In yet other embodiments,the support member 3102 can compress to conform to the shape of thespinous processes S. Similarly, in some embodiments, the proximalretention member 3 110 and the distal retention member 3112 aresubstantially rigid. In other embodiments, the retention members orportions thereof are elastically deformable, thereby allowing them toconform to the shape of the spinous processes.

In the illustrated embodiment, the spinal implant 3100 is held in thefirst configuration by an insertion tool (not shown) that overcomes theforce exerted by the biasing member 3136, thereby disposing a portion ofthe first elongate member 3130 within the pocket 3134 of the secondelongate member 3132. In this manner, the spinal implant 3100 can berepeatedly moved from the first configuration to the secondconfiguration, thereby allowing it to be repositioned and/or removedpercutaneously. As illustrated in FIG. 70, the first elongate member3130 and the second elongate member 3132 each include notches 3138configured to receive a portion of the insertion tool. When theinsertion tool is released, the biasing member 3136 is free to extend,thereby displacing a portion of the first elongate member 3130 out ofthe pocket 3134 of the second elongate member 3132. In this manner,portions of both the first elongate member 3130 and the second elongatemember 3132 are extended through the adjacent openings 3114 and to anarea outside of the support member 3102. In some embodiments, theproximal retention member 3110 and the distal retention member 3112 aretransitioned between their respective first and second configurationssimultaneously. In other embodiments, the proximal retention member 3110and the distal retention member 3112 are transitioned between theirfirst and second configurations serially.

As illustrated, the first elongate member 3130 and the second elongatemember 3132 each include one or more tabs 3140 that engage the side wall3108 of the support member 3102 when in the second configuration,thereby ensuring that the first and second elongate members remaincoupled to each other and that portions of the first and second elongatemembers remain suitably disposed within the support member 3102. Inother embodiments, the first elongate member 3130 and the secondelongate member 3132 are coupled to each other by other suitablemechanisms, such as mating tabs and slots configured to engage when theretention member reaches a predetermined limit of extension.

FIGS. 72, 73A and 73B are cross-sectional views of a spinal implant 3200according to an embodiment of the invention. FIG. 72 illustrates across-sectional front view of the spinal implant 3200 in a secondconfiguration, while FIGS. 73A and 73B illustrate a cross-sectional planview of the spinal implant 3200 in the second configuration and a firstconfiguration, respectively. The illustrated spinal implant 3200includes a support member 3202, a retention member 3210 and a rotatingmember 3250. Although shown and described as including only a singleretention member 3210, some embodiments can include one or moreadditional retention members having characteristics and functionalitysimilar to those described for the retention member 3210.

As shown in FIGS. 73A and 73B, the retention member 3210 is repeatablypositionable in a first configuration in which it is substantiallydisposed within the support member 3202, and a second configuration inwhich a portion the retention member 3210 is disposed outside of thesupport member 3102. When the spinal implant 3200 is in the firstconfiguration, it can be inserted between adjacent spinous processes,repositioned between adjacent spinous processes and/or removed from thepatient. When the spinal implant 3200 is in the second configuration,its lateral movement is limited, thereby allowing the desired positionof the support member 3202 to be maintained.

The support member 3202 includes a sidewall 3208 that defines an innerarea 3220 and multiple openings 3214 that connect the inner area 3220 toan area outside of the support member 3202. When the spinal implant 3200is in the first configuration, the retention member 3210 issubstantially disposed within the inner area 3220 of the support member3202, as shown in FIG. 73B. When the spinal implant 3200 is in thesecond configuration, a portion of the proximal retention member 3210extends through the openings 3214 to an area outside of the supportmember 3202. In the second configuration, the retention member 3210 isdisposed adjacent the spinous processes, thereby limiting lateralmovement of the spinal implant 3200.

The retention member 3210 includes an elongate member 3228 having twoend portions 3244, a central portion 3242, and a longitudinal axis L1(shown in FIG. 72). A portion of the elongate member 3228 is flexiblesuch that it can be wound along the rotating member 3250, as describedbelow. In some embodiments, the elongate member 3228 is monolithicallyformed such that it is flexible enough to be wound along the rotatingmember 3250 yet rigid enough to limit lateral movement of the supportmember 3202 when positioned in the second configuration. In otherembodiments, the elongate member 3228 includes separate components thatare coupled together to form the elongate member 3228. For example, thecentral portion 3242 of the elongate member 3228 can be a distinctcomponent having a greater amount of flexibility, while the end portions3244 can be distinct components having a greater amount of rigidity.

In the illustrated embodiment, elongate member 3228 has one or more tabs3240 that engage the side wall 3208 of the support member 3202 when inthe second configuration, thereby ensuring that the elongate member 3228does not freely extend entirely outside of the support member 3202. Inother embodiments, a portion of the elongate member 3228 is retainedwithin the support member 3202 by other suitable mechanisms. Forexample, the width of the central portion 3242 of the elongate member3228 can be greater than the width of the openings 3214, therebyensuring that a portion of the elongate member 3228 will remain withinthe support member 3202.

The rotating member 3250 defines an outer surface 3252 and a slot 3254through which the elongate member 3228 is disposed. The rotating member3250 has a longitudinal axis L2 (shown in FIG. 72) about which itrotates. As illustrated in FIG. 73B, as the rotating member 3250rotates, the elongate member 3228 is wound along the outer surface 3252of the rotating member 3250. This causes the elongate member 3228 tomove along its longitudinal axis L1, thereby causing the end portions3244 of the elongate member 3228 to be retracted inwardly through theopenings 3214. In this manner, the retention member 3210 can berepeatedly transitioned between the first configuration and the secondconfiguration.

In some embodiments, the rotating member 3250 is rotated using aninsertion tool (not shown) that includes a ratchet mechanism. Theinsertion tool can rotate the rotating member 3250 in a number ofdifferent ways, such as, for example, manually, pneumatically orelectronically.

FIGS. 74 and 75A-75C are cross-sectional views of a spinal implant 3300according to an embodiment of the invention. FIG. 74 illustrates across-sectional front view of the spinal implant 3300 in a secondconfiguration, while FIGS. 75A-75C illustrate a cross-sectional planview of the spinal implant 3300 in the second configuration, a firstconfiguration, and a third configuration, respectively. The illustratedspinal implant 3300 includes a support member 3302 and a retentionmember 3310. Although shown and described as including only a singleretention member 3310, some embodiments can include one or moreadditional retention members having characteristics and functionalitysimilar to those described for the retention member 3310.

As shown in FIGS. 75A-75C, the retention member 3310 is repeatablypositionable in a first configuration, a second configuration and athird configuration. A portion the retention member 3310 is disposedoutside of the support member 3302 when positioned in the secondconfiguration. The retention member 3310 is substantially disposedwithin the support member 3202 when positioned in each of the first andthird configurations. As illustrated in FIGS. 75B and 75C, theorientation of the retention member 3310 differs between the first andthird configurations. In this manner, the position of the spinal implant3300 can be positioned appropriately depending on the direction in whichit is being moved. For example, the spinal implant 3300 may bepositioned in the first configuration to facilitate lateral movement ofthe support member 3302 in a distal direction, such as during insertion.Conversely, the spinal implant 3300 may be positioned in the thirdconfiguration to facilitate lateral movement of the support member 3302in a proximal direction, such as during removal.

The support member 3302 includes a sidewall 3308 that defines an innerarea 3320 and multiple openings 3314 that connect the inner area 3320 toan area outside of the support member 3302. When the spinal implant 3300is in the second configuration, a portion of the proximal retentionmember 3310 extends through the openings 3314 to an area outside of thesupport member 3302.

The retention member 3310 includes a first elongate member 3330, asecond elongate member 3332, and a hinge 3360 having a longitudinal axisL2 (shown in FIG. 74). Each of the first elongate member 3330 and thesecond elongate member 3332 has a distal end portion 3344 that extendsthrough the openings 3314 when the spinal implant 3300 is in the secondconfiguration and a proximal end portion 3346 that is pivotally coupledto the hinge 3360. In use, the hinge 3360 moves in a direction normal toits longitudinal axis L2, as indicated by the arrows in FIGS. 75B and75C. The motion of the hinge is guided by a slot 3362 defined by theside wall 3308 of the support member 3302. The movement of the hinge3360 allows the each of the first elongate member 3330 and the secondelongate member 3332 to rotate about the longitudinal axis L2 of thehinge 3360, thereby positioning the distal end portion 3344 of eachelongate member substantially within the inner area 3320 of the supportmember 3302.

In some embodiments, the slot 3362 includes detents or any othersuitable mechanism (not shown) to maintain the hinge 3360 in the desiredposition. In other embodiments the hinge 3360 includes a biasing member(not shown) configured to bias the hinge 3360 in one of the first,second, or third configurations. In yet other embodiments, the elongatemembers include other suitable mechanisms to retain the retention memberin a desired configuration. Such mechanisms can include, for example,mating tabs and slots configured to lockably engage when the elongatemembers are in a desired configuration.

In some embodiments, the first elongate member 3330 and the secondelongate member 3332 are monolithically formed of a substantially rigidmaterial. In other embodiments, the first elongate member 3330 and thesecond elongate member 3332 include separate components having differentmaterial properties. For example, the distal end portion 3344 can beformed from a material having a greater amount of flexibility, while theproximal end portion 3346 can be formed from a substantially rigidmaterial. In this manner, movement of the spinal implant 3300 is notrestricted when a portion of the of the distal end portion 3344protrudes from the openings 3314 in either the first configuration orthe third configuration.

FIGS. 76A and 76B are cross-sectional front views of a spinal implant3400 according to an embodiment of the invention. The illustrated spinalimplant 3400 includes a support member 3402, a retention member 3410 anda rotating member 3450. As shown in FIGS. 76A and 76B, the retentionmember 3410 is repeatably positionable in a first configuration in whichit is substantially disposed within the support member 3402, and asecond configuration in which a portion the retention member 3410 isdisposed outside of the support member 3402. Although shown anddescribed as including only a single retention member 3410, someembodiments include one or more additional retention members havingcharacterstics and functionality similar to those described for theretention member 3410.

The support member 3402 includes a sidewall 3408 that defines an innerarea 3420 and multiple openings 3414 that connect the inner area 3420 toan area outside of the support member 3402. When the spinal implant 3400is in the second configuration, a portion of the proximal retentionmember 3410 extends through the openings 3414 to an area outside of thesupport member 3402.

The retention member 3410 includes a first elongate member 3430 and asecond elongate member 3432, each having a distal end portion 3444 thatextends through the openings 3414 when the spinal implant 3400 is in thesecond configuration, a proximal end portion 3446, and a longitudinalaxis L1. As illustrated, the proximal end portions 3346 are coupled bytwo elastic members 3468, such as a spring or an elastic band. In someembodiments, the proximal end portions 3346 are coupled by a singleelastic member. In other embodiments, the proximal end portions 3346 areindirectly coupled via the rotating member 3450. In such an arrangement,for example, a biasing member can be placed between the sidewall of thesupport member and each elongate member, thereby biasing each elongatemember against the rotating member.

In the illustrated embodiment, the elongate members each include one ormore tabs 3440 that engage the side wall 3408 of the support member 3402when in the second configuration, thereby ensuring that the elongatemembers 3430, 3432 does not freely extend entirely outside of thesupport member 3402. In other embodiments, the elongate members do notinclude tabs, but are retained within the support member 3402 solely bythe elastic members 3468. In yet other embodiments, the width of aportion of the elongate members can be greater than the width of theopenings 3414, thereby ensuring that the elongate members will remainwithin the support member 3402.

The rotating member 3450 defines an outer surface 3452 having aneccentric shape and includes a longitudinal axis (not shown) about whichit rotates. As illustrated in FIGS. 76A and 76B, as the rotating member3450 rotates about its longitudinal axis, a portion of the proximal endportion 3346 of the first elongate member 3430 and the second elongatemember 3432 engage the outer surface 3452 of the rotating member 3250.This causes the first elongate member 3430 and the second elongatemember 3432 to move along their respective longitudinal axes L1, therebycausing the end portions 3444 of each elongate member to be extendedoutwardly through the openings 3414, as indicated by the arrows in FIG.76A. In this manner, the retention member 3410 can be repeatedlytransitioned between the first configuration and the secondconfiguration.

In some embodiments, the rotating member 3450 is rotated using aninsertion tool (not shown) that includes a ratchet mechanism. Theinsertion tool can rotate the rotating member 3450 in a number ofdifferent ways, such as, for example, manually, pneumatically orelectronically.

FIGS. 77 and 78 illustrate a spinal implant 3500 according to anembodiment of the invention. FIG. 77 is a cross-sectional front view ofthe spinal implant 3500 in a second configuration. FIG. 78 is across-sectional plan view of the spinal implant 3500 taken along sectionA-A. The spinal implant 3500 includes a support member 3502 and aretention member 3510. Although only shown as being in a second orexpanded configuration, it is understood from the previous descriptionsthat the retention member 3510 is repeatably positionable in a firstconfiguration in which it is substantially disposed within the supportmember 3502, and the second configuration in which a portion theretention member 3510 is disposed outside of the support member 3502.

As illustrated, the retention member 3510 includes a first elongatemember 3530 and a second elongate member 3532. The first elongate member3530 is slidably disposed within a pocket 3534 defined by the secondelongate member 3532. The first elongate member 3530 and the secondelongate member 3532 each include one or more tabs 3540 that are coupledto the side wall 3508 of the support member 3502 by one or more biasingmembers 3536. In this manner, the retention member 3510 is biased in thefirst or retracted configuration. In other embodiments, the biasingmembers 3536 can be configured to bias the retention member 3510 in thesecond configuration. In yet other embodiments, the retention member3510 is not retained by a biasing member 3536, but rather uses othersuitable mechanisms to retain the desired configuration.

In use, the retention member 3510 is transitioned from the firstconfiguration to the second configuration by supplying a pressurizedfluid (not shown) to the pocket 3534 via valve 3570. The pressureexerted by the fluid on each of the first elongate member 3530 and thesecond elongate member 3532 overcomes the force exerted by the biasingmembers 3536, thereby causing a portion the first elongate member 3530to extend outwardly from the pocket 3534 of the second elongate member3132, thereby allowing a portion of each elongate member to extendthrough the adjacent openings 3514 and to an area outside of the supportmember 3502. Similarly, the retention member 3510 is transitioned fromthe second configuration to the first configuration by opening the valve3570 and relieving the pressure within the pocket 3534. In this manner,the spinal implant 3500 can be repeatedly moved from the firstconfiguration to the second configuration, thereby allowing it to berepositioned and/or removed percutaneously.

FIGS. 79A and 79B illustrate perspective views of a spinal implant 3600according to an embodiment of the invention. The spinal implant 3600includes a support member 3602, a proximal retention member 3610, adistal retention member 3612, and an elastic member 3668. The supportmember 3602 defines a longitudinal axis L1 and has a sidewall 3608 thatdefines an inner area 3620 and has an outer surface 3616. As illustratedin FIG. 79B, the outer surface 3616 defines an area A normal to thelongitudinal axis L1. As shown, the proximal retention member 3610 andthe distal retention member 3612 are each repeatably positionable in afirst configuration in which they are substantially disposed within thearea A (FIG. 79B), and a second configuration in which a portion of eachretention member 3610, 3612 is disposed outside of the area A (FIG.79A).

As illustrated, the proximal retention member 3610 and the distalretention member 3612 are coupled by the elastic member 3668, a portionof which is disposed within the inner area 3620 of the support member3602. In the illustrated embodiment, the elastic member 3668 has asidewall 3674 that defines a lumen 3676. In other embodiments, theelastic member can be, for example, a spring, an elastic band, or anyother suitable device for elastically coupling the proximal retentionmember 3610 and the distal retention member 3612.

The proximal retention member 3610 includes a first elongate member 3630and a second elongate member 3632, each of which are pivotally coupledto a connection member 3678 by a hinge 3660. Similarly, the distalretention member 3612 includes a first elongate member 3631 and a secondelongate member 3633 each of which are pivotally coupled to a connectionmember 3678 by a hinge 3660.

As illustrated in FIG. 79A, when the spinal implant 3600 is in thesecond configuration, the elastic member 3668 exerts a biasing force oneach connection member 3678, thereby causing the connection members 3678to remain adjacent to the support member 3602. In this configuration,the first elongate member 3630 and the second elongate member 3632 arefully extended. The spinal implant 3600 is transitioned from the secondconfiguration to the first configuration by stretching the elasticmember 3668, which allows the connection members 3678 to be disposedapart from the support member 3602, thereby allowing the elongatemembers to move within the area A, as illustrated in FIG. 79B. Thesupport member 3602 includes slots 3672 in which the end portion of eachelongate member can be disposed to maintain the spinal implant 3600 inthe first configuration.

The elastic member 3668 can be stretched by an insertion tool (notshown), a portion of which can be configured to be disposed within thelumen 3676 of the elastic member 3668. For example, a first portion ofan insertion tool can engage the connection member 3678 of the proximalretention member 3610 while a second portion of the insertion tool canengage the connection member 3678 of the distal retention member 3612.The tool can then be configured to exert an outward force on each of theconnection members 3678, thereby stretching the elastic member 3668 andallowing the spinal implant to transition from the second configurationto the first configuration.

While the spinal implants are shown and described above as having one ormore retention members that extend substantially symmetrically from asupport member when in a second configuration, in some embodiments, aspinal implant includes a retention member that extends asymmetricallyfrom a support member when in a second configuration. For example, FIGS.80-82 illustrate a spinal implant 3700 according to an embodiment of theinvention that includes a proximal retention member 3710 and a distalretention member 3712 that extend asymmetrically from a support member3702. As shown in FIGS. 80 and 81, the proximal retention member 3710and the distal retention member 3712 are each repeatably positionable ina first configuration in which they are substantially disposed withinthe support member 3702, and a second configuration in which a portioneach is disposed outside of the support member 3702.

The support member 3702 includes a sidewall 3708 that defines an innerarea 3720 and two openings 3714 that connect the inner area 3720 to anarea outside of the support member 3702. When the spinal implant 3700 isin the second configuration, a portion of the proximal retention member3710 and a portion of the distal retention member 3712 extend throughthe openings 3714 to an area outside of the support member 3702.

In the illustrated embodiment, the proximal retention member 3710 andthe distal retention member 3712 each include a first end portion 3746and a second end portion 3744. The first end portions 3746 of theproximal retention member 3710 and the distal retention member 3712 arecoupled by a connecting member 3782 that has a longitudinal axis L1(shown in FIG. 77). In some embodiments, the connecting member 3782, theproximal retention member 3710 and the distal retention member 3712 areseparate components that are coupled together to form the illustratedstructure. In other embodiments, the connecting member 3782, theproximal retention member 3710 and the distal retention member 3712 aremonolithically formed.

The connecting member 3782 defines a longitudinal axis L1 about which itrotates. As illustrated, as the connecting member 3782 rotates, theproximal retention member 3710 and the distal retention member 3712 alsorotate, thereby causing the end portions 3744 of the proximal retentionmember 3710 and the distal retention member 3712 to extend outwardlythrough the openings 3714. In this manner, the retention member 3210 canbe repeatedly transitioned between the first configuration and thesecond configuration.

In some embodiments, the connecting member 3782 is rotated using aninsertion tool (not shown) that includes a ratchet mechanism. Theinsertion tool can rotate the connecting member 3782 in a number ofdifferent ways, such as, for example, manually, pneumatically orelectronically.

In one embodiment, an apparatus includes a first body coupled to asecond body. The first body and the second body collectively areconfigured to be releasably coupled to an implant device configured tobe disposed between adjacent spinous processes. A first engaging portionis coupled to the first body, and a second engaging portion is coupledto the second body. The first engaging portion and/or the secondengaging portion is configured to be received within a first openingdefined by the implant device. The first body configured to be movedrelative to the second body such that a distance between the firstengaging portion and the second engaging portion is moved between afirst distance and a second distance, and simultaneously a length of theimplant device is moved between a first length and a second length.

In another embodiment, a kit includes an implant that is reconfigurablebetween an expanded configuration and a collapsed configuration whiledisposed between adjacent spinous processes. The implant has alongitudinal axis and defines an opening. A deployment tool isconfigured to be releasably coupled to the implant. The deployment toolincludes an engaging portion configured to be removably received withinthe opening of the implant and extend in a transverse direction relativeto the longitudinal axis when the deployment tool is coupled to theimplant. The deployment tool is configured to move the implant betweenthe collapsed configuration and the expanded configuration while theimplant is disposed between the adjacent spinous processes.

FIGS. 83 and 84 are schematic illustrations of a medical deviceaccording to an embodiment of the invention positioned between twoadjacent spinous processes. FIG. 83 illustrates the medical device in afirst configuration, and FIG. 84 illustrates the medical device in asecond configuration. The medical device 6000 includes an implant 6010and a deployment tool 6020. The implant 6010 includes a distal portion6012, a proximal portion 6014, and a central portion 6016. The implant6010 is configured to be inserted between adjacent spinous processes S.The central portion 6016 is configured to contact and provide a minimumspacing between the spinous processes S when adjacent spinous processesS move toward each other during their range of motion to preventover-extension/compression of the spinous processes S. In someembodiments, the central portion 6016 does not substantially distractthe adjacent spinous processes S. In other embodiments, the centralportion 6016 does distract the adjacent spinous processes S. The implant6010 and the deployment tool 6020 can each be inserted into a patient'sback and moved in between adjacent spinous processes from the side ofthe spinous processes (i.e., a posterior-lateral approach). The use of acurved insertion shaft assists in the use of a lateral approach to thespinous processes S.

The implant 6010 has a collapsed configuration in which the proximalportion 6014, the distal portion 6012 and the central portion 6016 sharea common longitudinal axis. In some embodiments, the proximal portion6014, the distal portion 6012 and the central portion 6016 define a tubehaving a constant inner diameter. In other embodiments, the proximalportion 6014, the distal portion 6012 and the central portion 6016define a tube having a constant outer diameter and/or inner diameter. Inyet other embodiments, the proximal portion 6014, the distal portion6012 and/or the central portion 6016 have different inner diametersand/or outer diameters.

The implant 6010 can be moved from the collapsed configuration to anexpanded configuration, as illustrated in FIG. 84. In the expandedconfiguration, the proximal portion 6014 and the distal portion 6012each have a larger outer perimeter (e.g., outer diameter) than when inthe collapsed configuration, and the proximal portion 6014 and thedistal portion 6012 each have a larger outer perimeter (e.g., outerdiameter) than the central portion 6016. In the expanded configuration,the proximal portion 6014 and the distal portion 6012 are positioned tolimit lateral movement of the implant 6010 with respect to the spinousprocesses S. The proximal portion 6014 and the distal portion 6012 areconfigured to engage the spinous process (i.e., either directly orthrough surrounding tissue and depending upon the relative position ofthe adjacent spinous processes S) in the expanded configuration. Forpurposes of clarity, the tissue surrounding the spinous processes S isnot illustrated.

In some embodiments, the proximal portion 6014, the distal portion 6012and the central portion 6016 are monolithically formed. In otherembodiments, one or more of the proximal portion 6014, the distalportion 6012 and/or the central portion 6016 are separate componentsthat can be coupled together to form the implant 6010. For example, theproximal portion 6014 and distal portion 6012 can be monolithicallyformed and the central portion 6016 can be a separate component that iscoupled thereto. These various portions can be coupled, for example, bya friction fit, welding, adhesive, etc.

The implant 6010 is configured to be coupled to the deployment tool6020. The deployment tool 6020 includes an elongate member 6022 and twoor more engaging portions 6024. In the embodiment shown in FIGS. 83 and84, there are two engaging portions 6024-1 and 6024-2 shown, but itshould be understood that more than two engaging portions 6024 can beincluded. The elongate member 6022 can include a first body portion 6026coupled to a second body portion 6028. In some embodiments, the firstbody portion 6026 is threadedly coupled to the second body portion 6028.The first body portion 6026 and the second body portion 6028 areconfigured to be moved relative to each other. For example, a threadedconnection between the first body portion 6026 and the second bodyportion 6028 can be used to decrease or increase a distance between thefirst body portion 6026 and the second body portion 6028. The first bodyportion 6026 and the second body portion 6028 can be a variety ofdifferent shapes and sizes, and can be the same shape and/or size, orhave a different shape and/or size than each other. For example, in someembodiments, the first body portion includes a straight distal end and astraight proximal end, and the second body portion includes a straightproximal end and a curved or rounded distal end. The curved distal endcan assist with the insertion of the deployment tool into a lumen of animplant and also with the insertion of the medical device into a portionof a patient's body.

The first engaging portion 6024-1 can be coupled to the first bodyportion 6026 and the second engaging portion 6024-2 can be coupled tothe second body portion 6028. The engaging portions 6024 can be, forexample, substantially rectangular, square, circular, oval,semi-circular, or quarter-moon shaped. The engaging portions 6024, canbe spring-loaded devices coupled to the elongate member 6022 of thedeployment tool 6020, such that the engaging portions 6024 are biasedinto a position transverse to a longitudinal axis A defined by theelongate member 6022 and extending from an outer surface of the elongatemember 6022. Upon force exerted on the engaging portions 6024, theengaging portions 6024 can be moved or collapsed to a positionsubstantially below the outer surface of the elongate member 6022. Theengaging portions 6024 can alternatively be coupled to an actuator (notshown) configured to move the engaging portions 6024 from a positiontransverse to the longitudinal axis A and extending from an outersurface of the elongate member 6022, to a position substantially belowthe outer surface of the elongate member 6022.

FIGS. 94-96 illustrate the movement of an engaging portion 6024 as itpasses by a spinous process S when an implant and deployment tool(collectively also referred to as medical device) are coupled togetherand being inserted between adjacent spinous processes. In some cases, asthe medical device is being inserted, an engaging portion 6024 extendingfrom a proximal portion of an implant may come into contact with aspinous process (or other tissue). To allow the engaging portion 6024 topass by the spinous process, the engaging portion 6024 can be moveddownward (as described above) so as to clear the spinous process. FIG.94 illustrates an engaging portion 6024 having a spring-biasedconstruction. The engaging portion 6024 includes a curved portion 6048that initially contacts the spinous process S as the medical device isbeing inserted adjacent a spinous process S. As the curved portion 6048contacts the spinous process S, the engaging portion 6024 is moveddownward at least partially into an interior of the implant 6010, asshown in FIG. 95. The engaging portion 6024 moves back to an extendedposition (e.g., extending transversely from a surface of the implant6010) after the engaging portion clears the spinous process S, as shownin FIG. 96, due to the bias of the spring (not shown).

The deployment tool 6020 can be used to move the implant 6010 from thecollapsed configuration to the expanded configuration, and vice versa,as will be discussed in more detail below. The first body portion 6026and the second body portion 6028 are collectively configured to beinserted at least partially into a lumen (not shown in FIGS. 83 and 84)of the implant 6010, such that at least one engaging portion 6024extends through an opening (not shown in FIGS. 83 and 84) defined by theimplant 6010. The implant 6010 can be configured with one or more suchopenings, each of which is configured to receive an engaging portion6024 disposed on the elongate member 6022 (e.g., the first body portion6026 or the second body portion 6028). The openings defined by theimplant 6010 can be, for example, the openings can be circular, oval,square, rectangular, etc. FIG. 85 illustrates an example of an implant6110 defining curved rectangular openings 6136, and FIG. 98 illustratesan implant 6310 defining curved round or circular openings 6336.

The openings are at least partially defined by an edge (not shown inFIGS. 83 and 84) on the implant 6010. The engaging portions 6024 on thedeployment tool 6020 include a surface (not shown in FIGS. 83 and 84)that is configured to engage or contact the edge of the openings of theimplant 6010 when the elongate member 6022 is inserted into the lumen ofthe implant 6010.

In use, the spinous processes S can be distracted prior to inserting theimplant 6010. When the spinous processes are distracted, a trocar can beused to define an access passage for the implant 6010. In someembodiments, the trocar can be used to define the passage as well asdistract the spinous processes S. Once an access passage is defined, theimplant 6010 can be inserted percutaneously and advanced between thespinous processes, distal end 6012 first, until the central portion 6016is located between the spinous processes S. In some embodiments, theimplant 6010 can be coupled to the deployment tool 6020 prior to beinginserted between the adjacent spinous processes. In other embodiments,the implant 6010 can be inserted between adjacent spinous processeswithout being coupled to the deployment tool 6020. In the latterconfiguration, after the implant 6010 is disposed between the adjacentspinous processes, the deployment tool 6020 can be inserted into thelumen defined by the implant 6010.

Once the implant 6010 is in place between the spinous processes, and thedeployment tool 6020 is in position within the lumen of the implant6010, the implant 6010 can be moved to the second configuration (i.e.,the expanded configuration) by actuating the deployment tool 6020. Forexample, when the deployment tool 6020 is inserted into the lumen of theimplant 6010, the first body portion 6026 is positioned at a firstdistance from the second body portion 6028, and the first engagingportion 6024-1 is positioned at a first distance from the secondengaging portion 6024-2, as shown in FIG. 83. The deployment tool 6020can then be actuated at a proximal end portion (e.g., by turning ahandle) (not shown in FIGS. 83 and 84) causing the threaded couplingbetween the first body portion 6026 and the second body portion 6028 tomove the first body portion 6026 and the second body portion 6028towards each other such that the first body portion 6026 is now at asecond distance (closer) from the second body portion 6028, as shown inFIG. 84. This movement likewise moves the first engaging portion 6024-1and the second engaging portion 6024-2 to a closer position relative toeach other. For example, in FIG. 83, the first engaging portion 6024-1is positioned at a distance from the second engaging portion 6024-2 thatis greater than a distance between the first engaging portion 6024-1 andthe second engaging portion 6024-2 shown in FIG. 84.

As the engaging portions 6024-1 and 6024-2 are moved relative to eachother, the surface (described above and described in more detail below)on the engaging portions 6024 imparts a force on the edge (describedabove and described in more detail below) of the opening defined by theimplant causing the implant to move from the collapsed configuration tothe expanded configuration.

The deployment tool 6020 is configured such that the deployment tool6020 can be removed from the implant 6010 after the implant has beenmoved to the expanded configuration. The implant can remain disposedbetween the spinous processes indefinitely or removed as needed. Forexample, the deployment tool 6020 can be reinserted into the lumen ofthe implant 6010 and actuated in an opposite direction to cause theimplant 6010 to be moved from the expanded configuration back to thecollapsed configuration. In the collapsed configuration, the implant canbe removed from the patient's body or repositioned to a new locationbetween the spinous processes.

In some embodiments, the implant 6010 is inserted percutaneously (i.e.,through an opening in the skin) and in a minimally-invasive manner. Forexample, as discussed in detail herein, the sizes of portions of theimplant are expanded after the implant is inserted between the spinousprocesses. Once expanded, the sizes of the expanded portions of theimplant are greater than the size of the opening. For example, the sizeof the opening/incision in the skin can be between 3 millimeters inlength and 25 millimeters in length across the opening. In someembodiments, the size of the implant in the expanded configuration isbetween 3 and 25 millimeters across the opening.

FIGS. 85-87 illustrate an implant according to an embodiment of theinvention. An implant 6110 includes a proximal portion 6114, a distalportion 6112, and a central portion 6116. The implant 6110 also definesmultiple openings 6132 on an outer surface of the implant 6110. Theopenings 6132 are in communication with a lumen 6158 (shown in FIG. 92)defined by the implant 6110. The openings 6132 are partially defined bya first edge 6136 and a second edge 6138. The implant 6110 includesexpandable portions disposed at the distal portion 6112 and the proximalportion 6114. The expandable portions 6140 can be coupled to the implant6110 or formed integral with the implant 6110, as shown in FIG. 97. Asshown in FIG. 97, elongated slots 6134 can be defined on an outersurface of the implant 6110. The elongated slots 6134 create weakenedareas on the implant 6110 that allow the expandable portions 6140 tofold when exposed to axial force, forming extensions 6142, as shown inFIG. 86.

The implant 6110 can be inserted between adjacent spinous processes (notshown) in a collapsed configuration, as shown in FIG. 85, and then movedto an expanded configuration, as shown in FIG. 86. The implant 6110 canthen be moved back to a collapsed configuration as shown in FIG. 87,which illustrates the expandable portions 6140 in a partially collapsedconfiguration. Although FIG. 87 shows a partially collapsedconfiguration, in some embodiments, the implant can be moved back to thecollapsed configuration as shown in FIG. 85.

To move the implant 6110 from the collapsed configuration to theexpanded configuration, and vice versa, a deployment tool, as describedabove and as shown in FIGS. 88-90, can be used. The deployment tool 6120includes an elongate member 6122 coupled to a handle 6144. The elongatemember 6122 includes a first body portion 6126 coupled to a second bodyportion 6128 through a threaded coupling 6150. A pair of engagingportions 6124-1 are disposed on the first body portion 6126, and a pairof engaging portions 6124-2 are disposed on the second body portion6128. The engaging portions 6124-1 and 6124-2 (also collectivelyreferred to as engaging portions 6124) include a surface 6146 and arounded portion 6148. The threaded coupling 6150 between the first bodyportion 6126 and the second body portion 6128 is used to move the firstbody portion 6126 and the second body portion 6128 such that a distancebetween the first body portion 6126 and the second body portion 6128 ischanged. For example, FIG. 89 illustrates a first distance d-1 betweenthe first body portion 6126 and the second body portion 6128, and FIG.90 illustrates a second distance d-2 between the first body portion 6126and the second body portion 6128. As shown in FIGS. 89 and 90, as thedistance between the first body portion 6126 and the second body portion6128 is changed, a distance between the engaging portions 6124-2 and6124-2 is also changed.

In use, the first body portion 6126 and the second body portion 6128 arecollectively disposed within the lumen 6158 of the implant 6110, suchthat the engaging portions 6124 extend through the openings 6132 andtransverse to an axis B defined by the implant 6110, as shown in FIGS.91-93. In this position, the surface 6146 of the engaging portions 6124is configured to contact the edge 6136 of the openings 6132. FIGS. 91and 92 illustrate the first body portion 6126 and the second bodyportion 6128 disposed within the lumen of the implant 6110, when theimplant is in a collapsed configuration. In this position, the firstbody portion 6126 is at a first distance from the second body portion6128, the engaging portions 6124-1 are at a first distance from theengaging portions 6124-2, and the implant has a first length L-1.

When the implant is positioned between spinous processes S, thedeployment tool 6120 can be actuated to move the implant 6110 to theexpanded configuration, as shown in FIG. 93. When the deployment tool6120 is actuated, the first body portion 6126 is moved closer to thesecond body portion 6128, and the engaging portions 6124-1 are movedcloser to the engaging portions 6124-2. When this occurs, the surface6146 on the engaging portions 6124 impart a force on the edge 6136 ofthe openings 6132, which axially compresses the implant 6110 until theimplant 6110 has a second length L-2, as shown in FIG. 93.

To move the implant 6110 back to the collapsed configuration, thedeployment tool 6120 can be reconfigured such that the surface 6146 ofthe engaging portions 6124 are positioned facing an opposite directionand configured to contact the edge 6138 of the implant 6110, as shown inFIG. 102. In some embodiments, the engaging portions 6124 can be, forexample, removed and re-coupled to the elongate member 6122 (e.g., thefirst body portion 6126 and the second body portion 6128) such that thesame engaging portions 6124 are simply repositioned. In otherembodiments, a second deployment tool can be used having engagingportions positioned in the opposite direction. In either case, thedeployment tool is inserted into the lumen 6158 of the implant 6110 asdone previously, such that the engaging portions 6124 extend through theopenings 6132 of the implant 6110 and the surface 6146 contacts the edge6136 of the implant 6110. The deployment tool 6120 is then actuated inan opposite direction (e.g., turned in an opposite direction) such thatthe first body portion 6126 and the second body portion 6128 arethreadedly moved further away from each other. In doing so, the engagingportions 6124-1 are moved further away from the engaging portions6124-2, and the surface 6146 of the engaging portions 6124 impart aforce on the edge 6138 (instead of edge of 6136) of openings 6132, whichmoves the implant 6110 back to the collapsed or straightenedconfiguration. Thus, the implant described in all of the embodiments ofthe invention can be repeatedly moved between the collapsed and expandedconfigurations as necessary to insert, reposition or remove the implantas desired.

FIG. 99 illustrates a deployment tool according to another embodiment ofthe invention. A deployment tool 6220 includes an elongate member 6222having a first body portion 6226 coupled to a second body portion 6228through a threaded coupling 6250. In this embodiment, the deploymenttool 6220 includes two sets of four (8 total) engaging portions 6224(only six engaging portions are shown in FIG. 99). A first set ofengaging portions 6224-1 are coupled to the first body portion 6226, anda second set of engaging portions 6224-2 are coupled to the second bodyportion 6228. The engaging portions 6224 include a first surface 6246and a second surface 6252. When the deployment tool 6220 is coupled toan implant, the first surface 6246 is configured to contact an edge ofan opening defined on the implant (such as edge 6136 on implant 6110),and the second surface 6252 is configured to contact an opposite edge onthe opening defined by the implant (such as edge 6138 on implant 6110).

Thus, in this embodiment, the deployment tool 6220 can be inserted intoan implant and used to move the implant between a collapsedconfiguration and an expanded configuration without having to repositionthe engaging portions 6224, or use a second deployment tool. To move theimplant from a collapsed configuration to an expanded configuration, thedeployment tool 6220 is actuated in a first direction. To move theimplant back to the collapsed configuration, the deployment tool 6220 isactuated in an opposite direction (e.g., turned in an oppositedirection). When the deployment tool 6220 is actuated to move theimplant from the collapsed configuration to the expanded configuration,the surface 6246 of the engaging portions 6224 impart a force on an edgeof an opening (e.g., edge 6136 on implant 6110), causing the implant tobe axially compressed, as previously described. When the deployment tool6220 is actuated to move the implant from the expanded configuration tothe collapsed configuration, the surface 6252 of the engaging portions6224 imparts a force on an opposite edge of the opening (e.g., edge 6138on implant 6110), causing the implant to be substantially straightenedas previously described.

FIG. 100 illustrates a deployment tool according to another embodimentof the invention. A deployment tool 6420 is similar to the deploymenttool 6220 described above, except in this embodiment, there are only twosets of two engaging portions 6424 (4 total). The engaging portions 6424are similar to the engaging portions 6224 except the engaging portions6424 are substantially rectangular shaped. The engaging portions 6424include a surface 6446 configured to contact an edge of an openingdefined by an implant, and a surface 6452 configured to contact anopposite edge of the opening defined by the implant.

FIG. 101 illustrates a deployment tool according to yet anotherembodiment of the invention. A deployment tool 6520 is similarlyconstructed and functions similarly to the previous embodiments. Thedeployment tool 6520 includes an elongate member 6522 that includes afirst body portion 6526 and a second body portion 6528. In thisembodiment, the first body portion 6526 and the second body portion 6528are smaller than illustrated in the previous embodiments, and engagingportions 6524 are coupled to the first body portion 6526 and the secondbody portion 6528 that are more elongate than previously shown.

A kit according to an embodiment of the invention can include at leastone implant and at least one deployment tool as described above. Forexample, a kit can include an implant and two deployment tools, onedeployment tool configured to be used to move the implant from acollapsed configuration to an expanded configuration, and anotherdeployment tool configured to be used to move the implant from theexpanded configuration to the collapsed configuration. Alternatively, akit can include a single deployment tool have multiple engaging portionsas described herein, that can be releasably coupled to an elongatemember of a deployment tool. For example, one type or style of engagingportion can be used to move the implant from a collapsed configurationto an expanded configuration, and another type or style of engagingportion can be used to move the implant from the expanded configurationto the collapsed configuration. The kit can include engaging portionshaving one of a variety of different shapes and sizes, such that a usercan select a particular engaging portion(s) for use in a particularapplication.

FIGS. 118-120 illustrate an implant 6610 according to another embodimentof the invention. The implant 6610 can be moved between a collapsedconfiguration, as shown in FIGS. 118 and 119, and an expandedconfiguration, as shown in FIGS. 120-122. The implant 6610 includes anouter shell 6670 having a distal portion 6612, a proximal portion 6614,and a central portion 6616. The outer shell 6670 defines a series ofopenings 6618 disposed between the distal portion 6612 and the centralportion 6616, and the proximal portion 6614 and the central portion6616. The outer shell 6670 includes a series of tabs 6620, a pair ofwhich are disposed opposite each other, along the longitudinal axis ofthe implant 6610, on either side of each opening 6618. The outer shell6670 also includes expandable portions 6640, which form extensions 6642that extend radially from the outer shell 6670 when the implant 6610 isin the expanded configuration. As illustrated best in FIGS. 120-122, thearrangement of the openings 6618 and the tabs 6620 effect the shapeand/or size of the extensions 6642. In some embodiments, the opposingtabs 6620 can be configured to engage each other when the implant 6610is in the expanded configuration, thereby serving as a positive stop tolimit the amount of expansion. In other embodiments, for example, theopposing tabs 6620 can be configured to engage each other during theexpansion process, thereby serving as a positive stop, but remain spacedapart when the implant 6610 is in the expanded configuration (see, forexample, FIGS. 120-122). In such embodiments, the elastic properties ofthe extensions 6642 can cause a slight “spring back,” thereby causingthe opposing tabs 6620 to be slightly spaced apart when the expansiondevice (also referred to as an insertion tool or a deployment tool) isdisengaged from the implant 6610.

As illustrated best in FIG. 118, when the implant is in the collapsedconfiguration, the expandable portions 6640 are contoured to extendslightly radially from remaining portions of the outer shell 6670. Inthis manner, the expandable portions 6640 are biased such that when acompressive force is applied, the expandable portions 6640 will extendoutwardly from the outer shell 6670. The expandable portions 6640 can bebiased using any suitable mechanism. In some embodiments, for example,the expandable portions can be biased by including a notch in one ormore locations along the expandable portion, as previously described. Inother embodiments, the expandable portions can be biased by varying thethickness of the expandable portions in an axial direction. In yet otherembodiments, the expandable portions can be stressed or bent prior toinsertion such that the expandable portions are predisposed to extendoutwardly when a compressive force is applied to the implant. In suchembodiments, the radius of the expandable portions is greater than thatof the remaining portions of the implant (e.g., the remainingcylindrical portions of the implant).

The implant 6610 also includes an inner core 6672 disposed within alumen 6658 defined by the outer shell 6670. The inner core 6672 isconfigured to maintain the shape of the implant 6610 during insertion,to prevent the expandable portions from extending inwardly into a regioninside of the outer shell 6670 during deployment and/or to maintain theshape of the central portion 6616 once the implant is in its desiredposition. As such, the inner core 6670 can be constructed to provideincreased compressive strength to the outer shell 6670. In other words,the inner core 6672 can provide additional structural support to outershell 6670 (e.g., in a direction transverse to the axial direction) byfilling at least a portion of the region inside outer shell 6670 (e.g.,lumen 6658) and contacting the walls of outer shell 6670. This canincrease the amount of compressive force that can be applied to theimplant 6610 while the implant 6610 still maintains its shape and, forexample, the desired spacing between adjacent spinous processes. In someembodiments, the inner core 6672 can define a lumen 6673, while in otherembodiments, the inner core 6672 can have a substantially solidconstruction. As illustrated, the inner core 6672 is fixedly coupled tothe outer shell 6670 with a coupling portion 6674, which is configuredto be threadedly coupled to the distal portion 6612 of the outer shell6670. The distal end of the coupling portion 6674 of the inner core 6672includes an opening 6675 configured to receive a tool configured todeform the distal end of the coupling portion 6674. In this manner oncethe inner core 6672 is threadedly coupled to the outer shell 6670, thecoupling portion 6674 can be deformed or peened to ensure that the innercore 6672 does not become inadvertently decoupled from the outer shell6670. In some embodiments, an adhesive, such as a thread-lockingcompound can be applied to the threaded portion of the coupling portion6674 to ensure the that the inner core 6672 does not inadvertentlybecome decoupled from the outer shell 6670. Although illustrated asbeing threadedly coupled, the inner core 6672 can be coupled to theouter shell 6670 by any suitable means. In some embodiments, forexample, the inner core 6672 can be coupled to the central portion 6616of the outer shell 6670 by, for example, a friction fit. In otherembodiments, the inner core 6672 can be coupled to the outer shell 6670by an adhesive. The inner core 6672 can have a length such that theinner core 6672 is disposed within the lumen 6658 along substantiallythe entire length of the outer shell 6670 or only a portion of thelength of the outer shell 6670.

The proximal portion of the inner core 6672 includes an opening 6673configured to receive a portion of an expansion device 7500 (alsoreferred to as an insertion tool or a deployment tool), as shown inFIGS. 125-132. The expansion device 7500 is similar to the expansiondevice 1500 shown and described above (see e.g. FIGS. 15-17). Theexpansion device 7500 differs, however, from expansion device 1500 inthat the expansion device 7500 includes spacer 7532 configured tocooperate with the inner core 6672 of the implant 6610. In such anarrangement, the threaded portion of rod 7570 of the expansion device7500 removably engages to the internal threads 6676 of the inner core6672 of the implant 6610, rather than coupling directly to the distalportion of the implant (as shown in FIGS. 15A and 15B). Although theinner core 6672 is shown as being threadedly coupled to the expansiondevice 7500, the inner core 6672 can be removably coupled to theexpansion device 7500 by any suitable means, such as a protrusion anddetent arrangement.

In use, once the implant 6610 is positioned on the implant supportportion 7530 of the expansion tool 7500 (see FIGS. 125 and 126), theimplant is inserted into the patient's body and disposed betweenadjacent spinous processes. Once disposed between adjacent spinousprocesses, the expansion device can be used to move the inner core 6672axially towards the proximal portion 6614 of the implant 6610 whilesimultaneously maintaining the position of the proximal portion 6614 ofthe implant 6610, as shown in FIGS. 130 and 132. In this manner, acompressive force is applied along the longitudinal axis of the outershell 6670, thereby causing the outer shell 6670 to fold or bend to formextensions 6642 as described above. As illustrated, a portion of thespacer 7532 is received within the receiving area 7542 of the supportportion 7530 as the implant 6610 is placed in the expandedconfiguration. Similarly, to move the implant 6610 from the expandedconfiguration to the collapsed configuration, the expansion device isactuated in the opposite direction to impart an axial force on thedistal portion 6612 of the outer shell 6610 in a distal direction,moving the distal portion 6612 distally, and moving the implant 6610 tothe collapsed configuration.

Once the implant 6610 is in its expanded configuration (see FIGS.129-132), the implant 6610 can be disengaged from the expansion device7500 by disengaging the distal portion of the rod 7570 from the opening6673. The rod 7570 can be disengaged by actuating the knob assembly 7515rotate the rod 7570 relative to the shaft 7520, as discussed above.

Although shown and described above without reference to any specificdimensions, in some embodiments, the outer shell 6670 can have acylindrical shape having a length of approximately 34.5 mm (1.36 inches)and a diameter between 8.1 and 14.0 mm (0.32 and 0.55 inches). In someembodiments, the wall thickness of the outer shell can be approximately5.1 mm (0.2 inches).

Similarly, in some embodiments, the inner core 6672 can have acylindrical shape having an overall length of approximately 27.2 mm(1.11 inches) and a diameter between 8.1 and 14.0 mm (0.32 and 0.55inches).

In some embodiments, the shape and size of the openings 6618 locatedadjacent the distal portion 6612 can be the same as that for theopenings 6618 located adjacent the proximal portion 6614. In otherembodiments, the openings 6618 can have different sizes and/or shapes.In some embodiments, the openings 6618 can have a length ofapproximately 11.4 mm (0.45 inches) and a width between 4.6 and 10 mm(0.18 and 0.40 inches).

Similarly, the shape and size of the tabs 6620 can be uniform ordifferent as circumstances dictate. In some embodiments, for example,the longitudinal length of the tabs 6620 located adjacent the proximalportion 6614 can be shorter than the longitudinal length of the tabs6620 located adjacent the distal portion 6612. In this manner, as theimplant is moved from the collapsed configuration to the expandedconfiguration, the tabs adjacent the distal portion will engage eachother first, thereby limiting the expansion of the expandable portions6640 adjacent the distal portion 6612 to a greater degree than theexpandable portions 6642 located adjacent the proximal portion 6614. Inother embodiments, the longitudinal length of the tabs can be the same.In some embodiments, the longitudinal length of the tabs can be between1.8 and 2.8 mm (0.07 and 0.11 inches). In some embodiments, the endportions of opposing tabs 6620 can have mating shapes, such as matingradii of curvature, such that the opposing tabs 6620 engage each otherin a predefined manner.

Although illustrated as having a generally rectangular shape, theexpandable portions 6640 and the resulting extensions 6642 can be of anysuitable shape and size. In some embodiments, for example, theexpandable portions can have a longitudinal length of approximately 11.4mm (0.45 inches) and a width between 3.6 and 3.8 mm (0.14 and 0.15inches). In other embodiments, size and/or shape of the expandableportions located adjacent the proximal portion 6614 can be differentthan the size and/or shape of the tabs 6620 located adjacent the distalportion 6612. Moreover, as described above, the expandable portions 6640can be contoured to extend slightly radially from the outer shell 6670.In some embodiments, for example, the expandable portions can have aradius of curvature of approximately 12.7 mm (0.5 inches) along an axisnormal to the longitudinal axis of the implant.

In some embodiments, the expandable portions 6640 and the outer shell6670 are monolithically formed. In other embodiments, the expandableportions 6640 and the outer shell 6670 are formed from separatecomponents having different material properties. For example, theexpandable portions 6640 can be formed from a material having a greateramount of flexibility, while the outer shell 6670 can be fonmed from amore rigid material. In this manner, the expandable portions 6640 can beeasily moved from the collapsed configuration to the expandedconfiguration, while the outer shell 6670 is sufficiently strong toresist undesirable defonnation when in use.

FIG. 103 is a flow chart illustrating a method according to anembodiment of the invention. A method includes at 6060, percutaneouslydisposing an expandable member at a first location between adjacentspinous processes within a body of a patient while the expandable memberis in a collapsed configuration. The expandable member is coupled to adeployment tool that includes an engaging portion configured to bereceived through an opening defined by the expandable member. In otherembodiments, the deployment tool can be coupled to the implant after theimplant has been disposed between the spinous processes. After theimplant has been disposed between the adjacent spinous processes, theexpandable member can be moved from the collapsed configuration to anexpanded configuration at 6062. To do this, the deployment tool can beactuated while the expandable member is disposed between the adjacentspinous processes such that the engaging portion of the deployment toolimparts a force to a first location on the expandable member and causesthe expandable member to move from the collapsed configuration to anexpanded configuration. After actuating the deployment tool such thatthe expandable member is moved from the collapsed configuration to theexpanded configuration, the deployment tool can optionally be removedfrom the expandable member, at 6064. In embodiments where the deploymenttool has been removed, the deployment tool can be subsequentlyreinserted into the expandable member.

At 6066, after the deployment tool has been actuated to move the implantfrom the collapsed configuration to the expanded configuration, thedeployment tool can be actuated again such that the engaging portionimparts a force to a second location on the expandable member differentfrom the first location on the expandable member, and the implant ismoved from the expanded configuration to the collapsed configuration.

After actuating the deployment tool such that the expandable member ismoved from the expanded configuration to the collapsed configuration,the expandable member can optionally be disposed at a second locationbetween the adjacent spinous processes different from the firstlocation, at 6068. In some embodiments, after the deployment tool isactuated such that the expandable member is moved from the expandedconfiguration to the collapsed configuration, the expandable member canoptionally be disposed at a second location outside of the body of thepatient, at 6070.

The various implants and deployment tools described herein can beconstructed with various biocompatible materials such as, for example,titanium, titanium alloyed, surgical steel, biocompatible metal alloys,stainless steel, plastic, polyetheretherketone (PEEK), carbon fiber,ultra-high molecular weight (UHMW) polyethylene, biocompatible polymericmaterials, etc. The material of a central portion of the implant canhave, for example, a compressive strength similar to or higher than thatof bone. In one embodiment, the central portion of the implant, which isplaced between the two adjacent spinous processes, is configured with amaterial having an elastic modulus higher than the elastic modulus ofthe bone, which forms the spinous processes. In another embodiment, thecentral portion of the implant is configured with a material having ahigher elastic modulus than the materials used to configure the distaland proximal portions of the implant. For example, the central portionof the implant may have an elastic modulus higher than bone, while theproximal and distal portions have a lower elastic modulus than bone. Inyet another embodiment, where the implant is configured with an outershell and an inner core. The outer shell can be configured with materialhaving a higher elastic modulus than the inner core (e.g., outer shellis made with titanium alloyed, while the inner core is made with apolymeric material). Alternatively, the outer shell can be configuredwith a material having a lower elastic modulus than the inner core(e.g., the outer shell is made with a polymeric material while the innercore is made with a titanium alloyed material).

An apparatus includes an elongate member having a proximal portionconfigured to be repeatedly moved between a first configuration and asecond configuration under, for example, an axial load or a radial load.The elongate member has a distal portion configured to be moved from afirst configuration to a second configuration under, for example, anaxial load or a radial load. A non-expanding central portion ispositioned between the proximal portion and the distal portion. Thenon-expanding central portion is configured to engage adjacent spinousprocesses upon spinal extension.

In some embodiments, the elongate member can have multiple portions thateach move from a first configuration to a second configuration, eithersimultaneously or serially. Additionally, the device, or portionsthereof, can be configured into many intermediate positions during themovement between the first configuration and the second configuration.For ease of reference, the entire device is referred to as being ineither a first configuration or a second configuration although itshould be understood that the device and/or portions thereof have arange of motion that includes many configuration including the firstconfiguration and the second configuration.

FIG. 104 is a schematic illustration of a medical device according to anembodiment of the invention adjacent two adjacent spinous processes. Themedical device 7010 includes a proximal portion 7012, a distal portion7014 and a central portion 7016. The medical device 7010 has a firstconfiguration in which it can be inserted between adjacent spinousprocesses S or removed from between adjacent spinous processes S. Thecentral portion 7016 is configured to contact the spinous processes S toprevent over-extension/compression of the spinous processes S. In someembodiments, the central portion 7016 does not substantially distractthe adjacent spinous processes S. In other embodiments, the centralportion 7016 does not distract the adjacent spinous processes S. Themedical device 7010 is inserted into a patient's back and moved inbetween adjacent spinous processes from the side of the spinousprocesses (i.e., a posterior-lateral approach). The use of a curvedinsertion shaft assists in the use of a lateral approach to the spinousprocesses S.

In the first configuration, the proximal portion 7012, the distalportion 7014 and the central portion 7016 share a common longitudinalaxis. In other embodiments, these portions do not share a commonlongitudinal axis. In some embodiments, the proximal portion 7012, thedistal portion 7014 and the central portion 7016 define a tube having aconstant inner diameter. In other embodiments, the proximal portion7012, the distal portion 7014 and the central portion 7016 define a tubehaving a constant outer diameter and/or inner diameter. In yet otherembodiments, the proximal portion 7012, the distal portion 7014 and/orthe central portion 7016 have different inner diameters and/or outerdiameters.

The medical device 7010 can be moved from the first configuration to asecond configuration as illustrated in FIG. 105. In the secondconfiguration, the proximal portion 7012 and the distal portion 7014 arepositioned to limit lateral movement of the device 7010 with respect tothe spinous processes S. The proximal portion 7012 and the distalportion 7014 are configured to engage the spinous process (i.e., eitherdirectly or through surrounding tissue) in the second configuration. Forpurposes of clarity, the tissue surrounding the spinous processes S isnot illustrated. Note the medical device and/or its portions can engagethe spinous processes S during all or just a portion of the range ofmotion of the spinous processes, S associated with the patient'smovements.

In some embodiments, the proximal portion 7012, the distal portion 7014and the central portion 7016 are monolithically formed. In otherembodiments, one or more of the proximal portion 7012, the distalportion 7014 and the central portion 7016 are separate components thatcan be coupled together to form the medical device 7010. For example,the proximal portion 7012 and distal portion 7014 can be monolithicallyformed and the central portion 7016 can be a separate component that iscoupled thereto. The proximal portion 7012, the distal portion 7014 andthe central portion 7016 can be the same or different materials. Thesevarious portions can be coupled, for example, by a friction fit,welding, adhesive, etc.

In use, the spinous processes S can be distracted prior to inserting themedical device 7010. Distraction of spinous processes is describedherein. When the spinous processes are distracted, a trocar can be usedto define an access passage for the medical device 7010. In someembodiments, the trocar can be used to define the passage as well asdistract the spinous processes S. Once an access passage is defined, themedical device 7010 is inserted percutaneously and advanced between thespinous processes, distal end 7014 first, until the central portion 7016is located between the spinous processes S. Once the medical device 7010is in place between the spinous processes, the proximal portion 7012 andthe distal portion 7014 are moved to the second configuration, eitherserially or simultaneously.

In some embodiments, the medical device 7010 is inserted percutaneously(i.e., through an opening in the skin) and in a minimally-invasivemanner. For example, as discussed in detail herein, when inserted, thesizes of portions of the implant are smaller than the size of theopening. The sizes of portions of the implant are expanded after theimplant is inserted between the spinous processes. Once expanded, thesizes of the expanded portions of the implant are greater than the sizeof the opening. When collapsed, the sizes of portions of the spinalimplant are again smaller than the size of the opening. For example, thesize of the opening/incision in the skin can be between 3 millimeters inlength and 25 millimeters in length across the opening. In someembodiments, the size of the implant in the expanded configuration isbetween 3 and 25 millimeters across the opening.

In some embodiments, the proximal portion 7012 and the distal portion7014 can be moved back to their original configuration or substantiallyclose to their original configuration and either repositioned betweenthe adjacent spinous processes or removed from the body in which theywere inserted.

FIG. 106 is a schematic illustration of a deformable element 7018 thatis representative of the characteristics of, for example, the distalportion 7014 of the medical device 7010 in a first configuration. Thedeformable member 7018 includes cutouts A, B, C along its length todefine weak points that allow the deformable member 7018 to deform in apredetermined manner. Depending upon the depth d of the cutouts A, B, Cand the width w of the throats T1, T2, T3, the manner in which thedeformable member 7018 deforms under an applied load can be controlledand varied. Additionally, depending upon the length L between thecutouts A, B, C (i.e., the length of the material between the cutouts),the manner in which the deformable member 7018 deforms can be controlledand varied.

FIG. 107 is a schematic illustration of the expansion properties of thedeformable member 7018 illustrated in FIG. 106. When a load is applied,for example, in the direction indicated by arrow X, the deformablemember 7018 deforms in a predetermined manner based on thecharacteristics of the deformable member 7018 as described above. Asillustrated in FIG. 107, the deformable member 7018 deforms most atcutouts B and C due to the configuration of the cutout C and the shortdistance between cutouts B and C. In some embodiments, the length of thedeformable member 7018 between cutouts B and C is sized to fit one sideof adjacent spinous processes.

The deformable member 7018 is stiffer at cutout A due to the shallowdepth of cutout A. As indicated in FIG. 107, a smooth transition isdefined by the deformable member 7108 between cutouts A and B. Such asmooth transition causes less stress on the tissue surrounding a side ofadjacent spinous processes than a more drastic transition (i.e., asteeper sngled wall) such as between cutouts B and C. The dimensions andconfiguration of the deformable member 7018 can also determine thetiming of the deformation at the various cutouts. The weaker (i.e.,deeper and wider) cutouts deform before the stronger (i.e., shallowerand narrower) cutouts.

FIGS. 108 and 109 illustrate a spinal implant 7100 in a firstconfiguration and second configuration, respectively. As shown in FIG.108, the spinal implant 7100 is collapsed in a first configuration andcan be inserted between adjacent spinous processes. The spinal implant7100 has a first deformable portion 7110, a second deformable portion7120 and a central, non-deformable portion 7150. The first deformableportion 7110 has a first end 7112 and a second end 7114. The seconddeformable portion 7120 has a first end 7122 and a second end 7124. Thecentral portion 7150 is coupled between second end 7114 and first end7122. In some embodiments, the spinal implant 7100 is monolithicallyformed.

The first deformable portion 7110, the second deformable portion 7120and the central portion 7150 have a common longitudinal axis A along thelength of spinal implant 7100. The central portion 7150 can have thesame inner diameter as first deformable portion 7110 and the seconddeformable portion 7120. In some embodiments, the outer diameter of thecentral portion 7150 is smaller than the outer diameter of the firstdeformable portion 7110 and the second deformable portion 7120.

In use, spinal implant 7100 is inserted percutaneously between adjacentspinous processes. The first deformable portion 7110 is inserted firstand is moved past the spinous processes until the central portion 7150is positioned between the spinous processes. The outer diameter of thecentral portion 7150 can be slightly smaller than the space between thespinous processes to account for surrounding ligaments and tissue. Insome embodiments, the central portion 7150 directly contacts the spinousprocesses between which it is positioned. In some embodiments, thecentral portion of spinal implant 7100 is a fixed size and is notcompressible or expandable. Note the spinal implant 7100 and/or thefirst deformable portion 7110, second deformable portion 7120, andcentral portion 7150 can engage the spinous processes during all or justa portion of the range of motion of the spinous processes associatedwith the patient's movement.

The first deformable portion 7110 includes, for example, expandingmembers 7115, and 7117. Between the expanding members 7115, 7117,openings (not illustrated) are defined. As discussed above, the size andshape of the openings influence the manner in which the expandingmembers 7115, 7117 deform when an axial load is applied. The seconddeformable portion 7120 includes expanding members 7125 and 7127.Between the expanding members 7125, 7127, openings (not illustrated) aredefined. As discussed above, the sizes and shapes of the openingsinfluence the manner in which the expanding members 7125, 7127 deformwhen an axial load is applied.

When an axial load is applied to the spinal implant 7100, the spinalimplant 7100 expands to a second configuration as illustrated in FIG.109. In the second configuration, first end 7112 and second end 7114 ofthe first deformable portion 7110 move towards each other and expandingmembers 7115, 7117 project substantially laterally away from thelongitudinal axis A. Likewise, first end 7122 and second end 7124 of thesecond deformable portion 7120 move towards one another and expandingmembers 7125, 7127 project laterally away from the longitudinal axis A.The expanding members 7115, 7117, 7125, 7127 in the second configurationform projections that extend to positions adjacent to the spinousprocesses between which the spinal implant 7100 is inserted. In thesecond configuration, the expanding members 7115, 7117, 7125, 7127inhibit lateral movement of the spinal implant 7100, while the centralportion 7150 prevents the adjacent spinous processes from movingtogether any closer than the distance defined by the diameter of thecentral portion 7150 during spinal extension.

The first end 7112 of the first deformable portion 7110 defines athreaded opening 7113. The central portion 7150 defines a secondthreaded opening 7155. The second end 7124 of the second defonnableportion 7120 defines a third threaded opening 7123. The threadedopenings 7113, 7155, 7123 receive portions of an actuator 7200 (see FIG.110) to move the first defonmable portion 7100 and the second deformableportion 7120 between their respective first configurations and secondconfigurations as described in greater detail herein. In someembodiments, the first threaded opening 7113 has a greater diameter thanthe second threaded opening 7155 and the third threaded opening 7123(see FIGS. 108-111). In some embodiments the second threaded opening7155 and the third threaded opening 7123 have the same diameter (seeFIGS. 108-111). In other embodiments, the first threaded opening 7113′and the second threaded opening 7155′ have the same diameter (see FIGS.112-115) and the third threaded opening 7123′ has a smaller diameterthan the first threaded opening and the second threaded opening. Thethreaded openings 7113, 7155, 7123, 7113′, 7155′, 7123′ are coaxiallyaligned. In other embodiments, the threaded openings can be anycombination of different or the same sizes.

The spinal implant 7100 is deformed by a compressive force impartedsubstantially along the longitudinal axis A of the spinal implant 7100.As illustrated in FIG. 110, the compressive force is imparted to thefirst defonmable portion 7110 by actuator 7200. The actuator includes afirst portion 7210 and a second portion 7220 movably received withinfirst portion 7210. In some embodiments, the second portion 7220 isslidably received within the first portion 7210. In other embodiments,the first portion 7210 and the second portion 7220 are threadedlycoupled. Each of the first portion 7210 and the second portion 7220 isprovided with external threads 7212 and 7222, respectively, to engagethe threaded openings 7113, 7155, 7123, 7113′, 7155′, 7123′.

As illustrated in FIG. 110, the compressive force is imparted to thefirst defonmable portion 7110, for example, by attaching the threadedportion 7212 to the first threaded opening 7113, attaching the threadedportion 7222 to the second threaded opening 7155 of the central portion7150, and drawing the second portion 7220 along the longitudinal axis Awhile imparting an opposing force against the first end 7112 of thefirst deformable portion 7110. The opposing force results in acompressive force causing the spinal implant 7100 to expand as discussedabove.

Once the first deformable portion 7110 is moved to its secondconfiguration, the threaded portion 7222 is threaded through the secondthreaded opening 7155 and threadedly coupled to the third threadedopening 7123. A compressive force is imparted to the second defonnableportion 7120 of the spinal implant 7100 by drawing the second portion7220 of the actuator in the direction indicated by the arrow F whileapplying an opposing force using the first portion 7210 of the actuatoragainst the spinal implant 7100. The opposing forces result in acompressive force causing the spinal implant to expand as illustrated inFIG. 111.

In some embodiments, the first defonnable portion 7110 and the seconddeformable portion 7120 can be expanded simultaneously when the secondportion 7220 of the actuator is coupled to the third threaded opening7123 and the first portion 7210 is coupled to the first threaded opening7113 and a compressive force is applied.

In embodiments in which the first threaded opening 7113′ has the samediameter as the second threaded opening 7155′ (best seen, for example,in FIGS. 112 and 113), the first threaded portion 7212 can be threadedlycoupled to the second threaded opening 7155′ and the second threadedportion 7222 can be threadedly coupled to the third threaded opening7123′. A compressive force is then applied between the central portion7150 and the second end 7124 of the second deformable portion 7120. Oncethe second deformable portion 7120 is in its second configuration, thefirst threaded portion 7212 can be threadedly coupled to the firstthreaded opening 7113′ and the first deformable portion 7110 can bedeformed into its second configuration.

After each of the first deformable portion 7110 and the seconddeformable portion 7120 are moved to the second expanded configuration,they subsequently can each be moved back to the first collapsedconfiguration by applying a force in the opposite direction alonglongitudinal axis A as illustrated, for example, in FIGS. 114-115. Inthis example, as discussed above, the spinal implant 7100 illustrated inFIGS. 112-115 has a first threaded opening 7113′ that has the samediameter as the second threaded opening 7155′.

With the first threaded portion 7212 coupled to the second threadedopening 7155′ and the second threaded portion 7222 coupled to the thirdthreaded opening 7123′, the second portion 7220 of the actuator 7200 ismoved in the direction indicated by arrow F to move the seconddeformable portion 7120 to its first collapsed configuration.

The first threaded portion 7212 is then coupled to the first threadedopening 7113′ and the second portion 7220 of actuator 7200 is againmoved in the direction of arrow F to move the first deformable portion7110 to its first collapsed configuration. When the entire spinalimplant 7100 has been completely collapsed, the spinal implant 7100 canbe repositioned between the spinous processes, or removed from itsposition between the spinous processes and removed from the body inwhich it was previously inserted. In some embodiments, the firstdeformable portion 7110 and the second deformable portion 7120 are notcompletely collapsed, but are instead moved to a configuration betweenfully expanded and fully collapsed. In this manner the spinal implant7100 may be repositioned or removed without being completely collapsed.

In some embodiments, the first deformable portion 7110 and the seconddeformable portion 7120 can be moved between the first and secondconfiguration using a balloon as an actuator. As illustrated in FIG.116, the second deformable portion 7120 is then moved from the secondconfiguration to the first configuration by imparting a longitudinalforce resulting from the inflation of a balloon 7300 with liquid and/orgas. As the balloon 7300 is inflated, it is forced against the centralportion 7150 and the second end 7124 of the second deformable portion7120. The force imparted by the balloon 7300 is generally in thedirection indicated by the arrow F. In some embodiments, the balloon7300 is a low-compliant balloon that is configured to expand to apredefined shape such that a force is imparted primarily in asubstantially longitudinal direction indicated by arrow F.

After the second deformable portion 7120 is moved substantially to itscollapsed configuration, the balloon 7300 is deflated and moved into thefirst deformable portion 7110. The balloon 7300 is then inflated asillustrated in FIG. 117 to impart a force in the direction indicated byarrow F. In some embodiments, the same balloon 7300 is used to collapseboth the first deformable portion 7110 and the second deformable portion7120. In other embodiments, a different balloon is used for each portion7110, 7120. Once the entire implant 7100 is moved to the firstconfiguration, the balloon is deflated and removed. In some embodiments,the balloon 7300 remains in the spinal implant 7100, and the spinalimplant 7100 and the balloon 7300 are removed simultaneously.

In some embodiments, the shaft on which the balloon is coupled hasexternal threads (not illustrated) to mate with the first threadedopening 7113, 7113′ and/or the second threaded opening 7155, 7155′. Inother embodiments, neither the openings nor the shaft on which theballoon is coupled are threaded. In yet other embodiments, the balloon7300 is inserted through the first portion 7210 of the actuator 7200.Alternatively, the actuator 7200 and the balloon 7300 can be used inconjunction with the spinal implant to expand and/or contract the firstdeformable portion 7110 and the second deformable portion 7120.

In other embodiments, there are no threaded openings defined in thespinal implant 7100. For example, the spinal implant can have multipleactuator-engaging portions that are not threaded, but are rather contactor bearing surfaces for various types of actuators. For example, anactuator (not illustrated) can be configured to grasp an outer surfaceof the spinal implant while simultaneously imparting a force against thedistal portion of the spinal implant to move the implant to a collapsedconfiguration.

The spinal implant 7100 can be made from, for example, stainless steel,plastic, polyetheretherketone (PEEK), carbon fiber, ultra-high molecularweight (UHMW) polyethylene, etc. or some combination thereof Forexample, the first deformable portion and the second deformable portioncan be made from one material and the non-expanding central portion canbe made from a different material. The material of such a non-expandingcentral portion can have a tensile strength similar to or higher thanthat of bone.

While various embodiments of the invention have been described above, itshould be understood that they have been presented by way of exampleonly, and not limitation. Where methods and steps described aboveindicate certain events occurring in certain order, those of ordinaryskill in the art having the benefit of this disclosure would recognizethat the ordering of certain steps may be modified and that suchmodifications are in accordance with the variations of the invention.Additionally, certain of the steps may be performed concurrently in aparallel process when possible, as well as performed sequentially asdescribed above. Thus, the breadth and scope of the invention should notbe limited by any of the above-described embodiments, but should bedefined only in accordance with the following claims and theirequivalents. While the invention has been particularly shown anddescribed with reference to specific embodiments thereof, it will beunderstood that various changes in form and details may be made.

For example, although the embodiments above are primarily described asbeing spinal implants configured to be positioned between adjacentspinous processes, in alternative embodiments, the implants areconfigured to be positioned adjacent any bone, tissue or other bodilystructure where it is desirable to maintain spacing while preventingaxial or longitudinal movement of the implant.

While the implants described herein were primarily described as notdistracting adjacent spinous processes, in alterative embodiments, theimplants can be configured to expand to distract adjacent spinousprocesses.

Although described as being inserted directly between adjacent spinousprocesses, in alternative embodiments, the implants described above canbe delivered through a cannula.

For example, although the swing arm 1700 is described as having anarcuate portion, in alternative embodiments of the invention, the entireswing arm 1700 may have an arcuate configuration. Additionally, theopening defined in the swing arm 1700 may extend the entire length ofthe swing arm 1700.

Although the swing arm 1700 is described and illustrated as having acircular opening at its end, in alternative embodiments, the opening canbe any shape and the shape of the portion of the working tool and/orspacer can be shaped to be matingly engage the opening of the swing arm.

Although the connection between the swing arm and the working tool areshown with the swing arm being the female component and the working toolbeing the male component, in alternative embodiments, the orientation ofthe male/female relationship may be reversed.

Although the first arm 1170 and second arm 1180 of the first clamp 1100are described as being resiliently coupled, in alternative embodimentsof the invention, the first arm 1170 and the second arm 1180 arepivotably or hingedly coupled.

Although the first clamp and second clamp are disclosed as having jawsthat engage opposite sides of a spinous process, in alternativeembodiments, the first clamp and second clamp may include otherconfigurations to engage the spinous process such as, for example,suction, adhesive, pins/projections, etc.

While the first clamp and second clamp are disclosed as being movablewith respect to one another, in alternative embodiments, the first clampor the second clamp may be fixed in position, with the other clampmoving relative to the fixed clamp.

While the first arm and the second arm of the clamp are shown as beingresiliently biased apart from one another, in alternative embodiments,the first arm and the second arm can be manually moved towards and awayfrom one another using a different configuration (e.g., scissorconfiguration).

Although embodiments are disclosed that illustrate the wire beingcoupled to the swing arm using a retainer, in alternative embodiments, aretainer need not be used. The wire can be coupled to the swing armusing other retention methods, such as, for example, a slit in which thewire can be clamped.

Additionally, although the working tool 1840 is disclosed as a trocartip, the working tool may be any working tool such as, for example, aspacer, a balloon actuator, a bone tamp, etc.

Although the embodiments above are primarily described as being spinalimplants configured to be positioned between adjacent spinous processes,in alternative embodiments, the implants are configured to be positionedadjacent any bone, tissue or other bodily structure where it isdesirable to maintain spacing while preventing axial or longitudinalmovement of the implant.

While the implants described herein were primarily described as notdistracting adjacent spinous processes, in alterative embodiments, theimplants can be configured to expand to distract adjacent spinousprocesses.

Although described as being inserted directly between adjacent spinousprocesses, in alternative embodiments, the implants described above canbe delivered through a cannula.

Although the actuator used to move the spinal implant from the expandedconfiguration to the collapsed configuration is described as a rodassembly or a balloon, in alternative embodiments the actuator can beany device configured to impart a longitudinal force sufficient to movethe implant to its collapsed configuration. For example, the actuatorcan be a piston/cylinder assembly, a ratchet assembly, or the like.

1. An apparatus, comprising: an outer body defining an interior region,at least a portion of the outer body configured to be disposed betweenadjacent spinous processes; and an inner body disposed within theinterior region of the outer body and having a distal end portioncoupled to a distal end portion of the outer body, a proximal endportion of the inner body configured to removably receive a tool to movethe outer body between a collapsed configuration and an expandedconfiguration.
 2. The apparatus of claim 1, wherein a distal end portionof the outer body has a tapered shape configured to facilitate insertionof the outer body from a common side of the adjacent spinous process. 3.The apparatus of claim 1, wherein the outer body defines a first tab anda second tab, the first tab and the second tab collectively configuredto limit expansion of the outer body when the outer body is moved fromthe collapsed configuration to the expanded configuration.
 4. Theapparatus of claim 1, wherein the inner body is configured tosubstantially maintain a shape of the outer body when the outer body isdisposed between adjacent spinous processes.
 5. The apparatus of claim1, wherein the inner body is configured to bear a load exerted by theadjacent spinous processes.
 6. The apparatus of claim 1, wherein theouter body has a first extension and a second extension spaced adistance apart from the first extension along a longitudinal axisdefined by the outer body when the outer body is in the expandedconfiguration.
 7. The apparatus of claim 1, wherein the outer body has afirst extension and a second extension spaced a distance apart from thefirst extension along a longitudinal axis defined by the outer body whenthe outer body is in the expanded configuration, the first extensionhaving a length in a direction substantially transverse to thelongitudinal axis greater than a length of the second extension in adirection substantially transverse to the longitudinal axis.
 8. Theapparatus of claim 1, wherein the tool is configured to apply an axialload in a distal direction on a proximal portion of the outer body andan axial force in a proximal direction on a proximal portion of theinner body to move the outer body between the collapsed configurationand the expanded configuration.
 9. The apparatus of claim 1, wherein theouter body includes a central portion configured to maintain a minimumspacing between the adjacent spinous processes, the outer body furtherincludes an expandable distal portion and an expandable proximalportion.
 10. The apparatus of claim 1, wherein when the outer body is inthe expanded configuration, a first portion of the outer body isconfigured to contact the adjacent spinous processes during at least aportion of a range of motion of the adjacent spinous processes, and asecond portion of the outer body is configured to retain the outer bodybetween the adjacent spinous processes.
 11. The apparatus of claim 1,wherein the distal end portion of the inner body is threadedly coupledto the distal end portion of the outer body.
 12. The apparatus of claim1, wherein the distal end portion of the inner body is fixedly coupledto the distal end portion of the outer body.
 13. The apparatus of claim1, wherein the proximal end portion of the inner body is configured tothreadedly couple to the tool.
 14. An apparatus, comprising: an outerbody having a collapsed configuration and an expanded configuration; andan inner body disposed within an interior region defined by the outerbody and having a distal end portion coupled to a distal end portion ofthe outer body, the inner body having an inner threaded portionconfigured to threadedly couple to a deployment tool configured to exerta compressive axial force on the outer body to move the outer bodybetween the expanded configuration and the collapsed configuration whileat least a portion of the outer body is disposed between adjacentspinous processes.
 15. The apparatus of claim 14, wherein the outer bodydefines a first tab and a second tab, the first tab and the second tabcollectively configured to limit expansion of the outer body when theouter body is moved from the collapsed configuration to the expandedconfiguration.
 16. The apparatus of claim 14, wherein the inner body isconfigured to substantially maintain a shape of the outer body when theouter body is disposed between adjacent spinous processes.
 17. Theapparatus of claim 14, wherein the inner body is configured to bear aload exerted by the adjacent spinous processes.
 18. The apparatus ofclaim 14, wherein the outer body has a first extension and a secondextension spaced a distance apart from the first extension along alongitudinal axis defined by the outer body when the outer body is inthe expanded configuration.
 19. The apparatus of claim 14, wherein theouter body has a first extension and a second extension spaced adistance apart from the first extension along a longitudinal axisdefined by the outer body when the outer body is in the expandedconfiguration, the first extension having a length in a directionsubstantially transverse to the longitudinal axis greater than a lengthof the second extension in a direction substantially transverse to thelongitudinal axis.
 20. The apparatus of claim 14, wherein the deploymenttool is configured to apply an axial load in a distal direction on aproximal portion of the outer body and an axial force in a proximaldirection on a proximal portion of the inner body to move the outer bodybetween the collapsed configuration and the expanded configuration. 21.The apparatus of claim 14, wherein the outer body includes a centralportion configured to maintain a minimum spacing between the adjacentspinous processes, the outer body further includes an expandable distalportion and an expandable proximal portion.
 22. The apparatus of claim14, wherein when the outer body is in the expanded configuration, afirst portion of the outer body is configured to contact the adjacentspinous processes during at least a portion of a range of motion of theadjacent spinous processes, and a second portion of the outer body isconfigured to retain the outer body between the adjacent spinousprocesses.
 23. The apparatus of claim 14, wherein the distal end portionof the inner body is threadedly coupled to the distal end portion of theouter body.
 24. The apparatus of claim 14, wherein the distal endportion of the inner body is fixedly coupled to the distal end portionof the outer body.
 25. A method, comprising: inserting percutaneouslyinto a tissue an implant having an outer body and an inner body disposedwithin an interior region of the outer body while the outer body is in acollapsed configuration; disposing the implant between adjacent spinousprocesses; and actuating a deployment tool to move the outer body fromthe collapsed configuration to an expanded configuration while at leasta portion of the implant is disposed between the adjacent spinousprocesses, a distal portion of the deployment tool being removablycoupled to a proximal portion of the inner body.
 26. The method of claim25, further comprising: after the actuating, removing the deploymenttool from within the opening of the inner body.
 27. The method of claim25, further comprising: after the actuating, actuating the deploymenttool to move the outer body from the expanded configuration to thecollapsed configuration while the portion of the implant is disposedbetween the adjacent spinous processes.
 28. The method of claim 25,wherein the actuating the deployment tool includes exerting an axialforce in a distal direction on a proximal portion of the outer body andan axial force in a proximal direction on a proximal portion of theinner body.
 29. The method of claim 25, wherein the inserting thedeployment tool includes threadedly coupling the deployment tool to theinner body.
 30. The method of claim 25, wherein the disposing theimplant includes disposing the implant at a first location between theadjacent spinous processes, the method further comprising: after theactuating, actuating the deployment tool to move the outer body from theexpanded configuration to the collapsed configuration; and disposing theimplant at a second location between the adjacent spinous processesdifferent from the first location while the outer body is in thecollapsed configuration.
 31. The method of claim 25, further comprising:defining a percutaneous path to a location between the adjacent spinousprocesses, the inserting being along the percutaneous path.
 32. Themethod of claim 25, further comprising: defining a percutaneous path toa location between the adjacent spinous processes, the percutaneous pathbeing curved and approaching the location from a common side of theadjacent spinous processes, the inserting being along the percutaneouspath and from the common side of the adjacent spinous processes.
 33. Akit, comprising: an implant being reconfigurable between an expandedconfiguration and a collapsed configuration while disposed betweenadjacent spinous processes, the implant having an outer body and aninner body coupled to the outer body; and a deployment tool configuredto be releasably coupled to the inner body, the deployment toolconfigured to move the outer body between the collapsed configurationand the expanded configuration while the implant is disposed between theadjacent spinous processes.
 34. The kit of claim, 33, wherein the innerbody is disposed within an interior region defined by the outer body.35. The kit of claim 33, wherein the deployment tool is configured toimpart an axial force on a proximal end of the outer body to move theouter body between the collapsed configuration and the expandedconfiguration.
 36. The kit of claim 33, wherein when the implant is inthe expanded configuration, a first portion of the implant is configuredto contact the adjacent spinous processes during at least a portion of arange of motion of the adjacent spinous processes, and a second portionof the implant is configured to retain the implant between the adjacentspinous processes.
 37. The kit of claim 33, wherein the inner bodydefines an opening on a proximal end portion, the deployment tool isconfigured to be received within the opening.
 38. The kit of claim 33,wherein a distal end portion of the inner body is fixedly coupled to adistal end portion of the outer body.
 39. The apparatus of claim 33,wherein a distal end portion of the inner body is threadedly coupled toa distal end portion of the outer body.
 40. The kit of claim 33, furthercomprising: a trocar configured to define a percutaneous path to alocation between the adjacent spinous processes.
 41. The kit of claim33, further comprising: a trocar configured to define a percutaneouspath to a location between the adjacent spinous processes, the trocarhaving a tapered distal end portion configured to distract the adjacentspinous processes as the tapered distal end portion is moved between theadjacent spinous processes.
 42. The apparatus of claim 33, wherein thedeployment tool is configured to be threadedly coupled to a proximalportion of the inner body.
 43. The apparatus of claim 33, wherein theouter body defines a first tab and a second tab, the first tab and thesecond tab collectively configured to limit expansion of the outer bodywhen the outer body is moved from the collapsed configuration to theexpanded configuration.
 44. The apparatus of claim 33, wherein the innerbody is configured to bear a load exerted by the adjacent spinousprocesses.
 45. The apparatus of claim 33, wherein the outer body has afirst extension and a second extension spaced a distance apart from thefirst extension along a longitudinal axis defined by the outer body whenthe outer body is in the expanded configuration.
 46. The apparatus ofclaim 33, wherein the outer body includes a central portion configuredto maintain a minimum spacing between the adjacent spinous processes,the outer body further includes an expandable distal portion and anexpandable proximal portion.